How to handle a Gmom that just doesn't get it!

Okay, I'm not sure where to post this but as I think it's attachment related I figured this might be the place to ask. I could really use any advice with handling my mother! She just doesn't GET that she has to treat me like my son's mother and it's really harming him when we're around her. Okay, so for background: My son came home last November from Ethiopia on his "official" 2nd birthday (probably more like 18-20 mos then). He'd been through a few caretakers already: His parents, who passed on, then an aunt who simply didn't have the resources to care for him, then his nanny and the other nannies at the orphanange, and then onto us. He was one of the shyest kids at the orphanage, cried a lot, and shrieked his head off for the first few days we had him. No honeymoon period with this kid! We'd been planning to do a steady move over from his nanny to us during the course of our week there (not long enough!) but realized that wasn't working and in the short time we had we figured it would be better to simply take custody and be his only caretakers 24/7. That worked pretty much, except that the nannies kept trying to take him from us to "help" (works with most kids and the parents appreciate it) but this would always set us back to square one so we ended up spending a loooot of time in our room and we wore him for days, other than when he slept at night (took naps on us). His feet didn't touch the floor for like the first 3 days we had him! He actually bonded pretty quickly and has been steadily getting better and better. By the time we reached our airport he was showing us shy smiles, within a week of being home he decided I was mommy and tried to nurse, and within a month or so he was pretty much totally comfortable with us. Everyone who sees him (social workers, Drs, other adoptive families, etc) all can't believe how well attached he is. He's just a happy, giggly, smart, talkative, energetic and generally well behaved but still mischievous little boy, and he's become very attached to both my husband and I, almost without question. There's only one problem: My mother. My mother, as well meaning as she may be, continuously usurps my role. He's a little hurt? She shoves everyone out of the way to go help him and I can't get to him. She feeds him all the time without asking me first if it's okay, even if I'm giving him food myself. She picks him up and walks off with him when we're out, she always has to repeat what I say if I ask him something (ex. "you need to go potty" "Oh, do you need to go potty Paxie? Go potty with Mama? Hmm? Potty?"), she immediately answers for me when people ask how he's doing, calls him "my boy" or "my baby" and refuses to call him something else saying "he's your son but he's MY baby!", literally won't leave him alone for a second when she's near, follows us around when we're with him even to the bathroom where she'll open the door and just stare at him grinning, etc. I've asked her repeatedly to stop doing certain things, like "please don't just grab him from the carseat while I'm getting my things and walk off with him and scare the crap out of my because my son is missing" or "please stop feeding him sweet things while I'm trying to feed him real food," you know, things that make sense. She even just grabbed him on our first day at church after coming home! Everyone was there to greet us at the door and she just grabbed him and walked off, smiling triumphantly, made it almost to the door with us yelling "hey, stop! Come back! Can you let me hold my son please?" We finally got her to stop close to the entrance and she seemed shocked that we'd want to hold our new son...:confused: She's relatively good about listening to me now, and she is trying I think, but... she just doesn't get it! I'm not sure if it's her very competitive nature coming out that makes her do this or if she really just is that blinded by loving him or what. Either way it shouldn't matter because it's HURTING him. He's always happy to see her but after some time with her he's often unhappy with me, and the longer our time is with her the less he even is willing to listen to me or make eye contact with me. I thought I was just being petty or that this was just normal until today. Today was the first time she watched him by herself for any significant amount of time while he was awake. I had a Drs apt and he freaks out in Drs offices (so many shots since coming home!), so my mom volunteered to stay with him in the waiting room and play with the kids stuff there. The appointment took forever, almost 2 hours because I was a new patient, and by the time I came out he wanted NOTHING to do with me. My mother says he was a perfect angel, and come to find out she went ahead and fed him food AGAIN when she didn't ask me if it was okay (I brought a snack, showed it to her, she nodded and failed to tell me she brought her own snack that she shared with him after I left). Not a big deal, though her repeatedly doing that when I ask her not to bothers me to no end. The big thing was how he reacted to being alone with her for 2 hours. He only wanted her and when he saw me he acted almost exactly how he did back at the orphanage. No eye contact except for when he'd turn to slap or punch as hard as he could (pretty hard, cheek still stings a tiny bit), and he was shrieking, sobbing uncontrollably, kept throwing himself to the floor, throwing shoes, hitting me with his shoe, kicking, spitting, screaming at me and scolding me, etc. He does not act like this normally! It was awful, a complete repeat of where he was 6.5 months ago only every now and then he's stop screaming for a second and cry "huuuuug!" and reach for me and held on so tight.... I just about started sobbing myself. My mother, of course, kept trying to tell me that he was only upset because I was gone for so long and it's natural for kids to be angry (thanks mom, really need you lecturing at me while I'm trying to calm my kid down). After 20+ minutes of him not calming down we got him in the car and drove around for a bit (made him calm) then went to lunch. Big mistake. My mother fed him AGAIN even though I keep asking her not too! Feeding is like the biggest attachment tool we had and what really seemed to bond him to us was us feeding him. So there we are at the restaurant, he's pretty calmed down, and I'm putting food on his plate and suddenly my mother just hands him some of her food without asking, makes sure to place it right in his hand and smile and, of course, he turns to look at me then starts shrieking his lungs off! He wouldn't stop! We had to leave the restaurant while he was holding onto my shoulder, half hugging and half slapping. I'm so frustrated now! We keep telling my mom that she HAS to respect us as his parents, that she HAS to stop doing these little things that usurp our roles because he's picking up on it! And given that he's already lost 3 mother figures I'm not surprised at all that he's still questioning whether or not her acting like his mom all the time means that I'm actually not going to be his mom forever. I would worry that it's the time I spend away from him that's upsetting him but it's not. I can leave him in the church nursery for forever and he's a happy camper! Same with friends watching him for a bit. None of them try to act like his mother, all defer to me, all show respect for me, and he's so much happier in these situations. I just have no idea how to handle my mother! I have no doubt that she loves my son and I know she's trying very hard to be a good grandmother to him, but she just doesn't get this attachment stuff even though we've spoken to her at length about it! It just boggles my mind! Okay, so I do not want to turn my son into a bargaining chip, and I don't want to cut my mother out of his life (we're down to one visit a week as is), but I'm just not sure how I can make her understand that she NEEDS to listen to us, and yes sometimes we are going to sound bizarrely strict to her and yeah sometimes we are overreacting, but we're still his parents and we only have his best interests at heart. And if you could have seen his face while he was crying today... all red and poofy and angry and sad and just PETRIFIED, with tears streaked down and a runny nose, and that scared look in his eyes... :( It was like I felt my heart tearing in two for him and he was hitting me but also hugging soooooo tight, nails dug into my skin... Sooo, any advice on how to educate my mother, set ultimatums, deal with this at all but still have her be a part of his life? Because general conversation and even pleading doesn't seem to be helping (maybe a bit but not as much as we need). If you can't offer advice, care to commiserate? I can't be the only one who's family members just don't understand that while he's "normal" 99.99% of the time he's still going to have that fear there, and while he's pretty much fully attached yeah he's still not done attaching and things can still happen to set us back. In case y'all are wondering, he was happy as a clam this afternoon after spending a few hours alone at home with mommy and daddy, playing and hugging and eating daddy's bday cake (or at least the little sugar soccer balls he chose to decorate it). Doesn't look like any long term damage from earlier, but I do not want it happening again if I can help it! Oh, and sorry it's so long! I think I'm literally incapable of writing anything short.