DD BMom is Getting Married & Moving :(

Let me start with alittle history... Four years ago we met a scared GIRL uncertain of her future & her newborn daughters future. She had to trust in total strangers to raise her daughter & love her! She trusted that we would keep our promises to her & that she would be able to watch her daughter grow through not only TONS of pictures but with visits as well. We have gone WAY beyond our promises!! She has become so close to our family, she has BECOME family. We love her to death!! Of all 3 of our adoptions, our relationship with her is the strongest! Fast forward to now... We have had the honor to watch that girl grow into a young woman who we are VERY proud of! She is in college & getting GREAT grades! She met the man of her dreams & last week we found out she is getting married on August 11th!! I cried when I found out. I felt like our little girl was growing up too fast! LOL THEN she told us they were having a baby! I cried aain! I was so happy. Then she told me they were moving to Oklahome, we are in WI. I cried again, but because I am sad. That is SOOOOOO far away! "M" visits us 4-5 times a year, stays for the weekend at least! Now we won't see her as much. She will have a baby, be still in school & a husband. I feel so selfish! I will really miss her. I'm also really scared for our daughter! Now I am the one uncertain of her future! Our daughter has some special needs. She has Early Onset Childhood Bipolar & PDD, which is a form of Autism. This has been very hard for "M" to accept & deal with. I knew one day "M" wuld grow up, get married & have more children. "M" & I talked about it alot. Our DD was suppose to be her Flower Girl, only NO ONE in "M's" extended family knows about our DD. Only "m's" Mom, Dad & Sister & of course her Fiance. Everyone will be so excited & fussing over the new baby, but no one knows about our DD. I'm afraid that with the problems our DD has, the fact that no one knows about her & this distance between "M" & our family, that our DD will be in the background now. Not being replaced because I KNOW how much "M" LOVES her!! But, I know how upset "M" is with the problems DD has & I don't want her to, I don't know... Like I said before, I now feel just a SMALL fraction of what she may have felt 4 years ago...so uncertain & scared. I shared these feelings with "M". She assured me she will ALWAYS be in our DD's life. I'm just freaked out! LOL Our DD NEEDS "M" to be in her life. "I" need "M" to be in her life. LOL Am I crazy?? Do I sound out of my mind that I am the one who is scared!? I worry endlessly about this. I know I shouldn't, but I love our DD so much & keeping her Birth Family in her life is something very important to us. Please don't get me wrong & think I am not happy for her because I am EXTREMELY happy for "M"!!! Like I said, we are VERY proud of who she is & is becoming! I just need some reassurance or something. ANYONE else ever feel this way or go through this?? The weird thing is, we have 2 other adopted children. Both have thier BMoms have had other children since they were adopted & one is getting married in February but I'm not feeling this way about them! Deb