Facebook and kinship care

Kinship care is a much messier awkward animal than "standard" foster care, and this is just one of many reasons ... I am not a big Facebook user, but I do use it to keep in touch with family scattered around. I absolutely do not talk about my nephew's case and have never even mentioned that he's in care, but I do post pics of him sometimes. (Yes, I eventually learned from here that you're not supposed to do this, but since I was never told any of the "rules", technically I don't know this. For all I know DHS would think it's okay since it's kinship. I post pics of my other nephews, too, who are not in care.) The majority of family unfriended my sister (nephew's mom) before her kids came into care, because of a bad family fall-out. A handful of extended family who have no idea what happened still have her as friends. So I have some "friends" in common with nephew's mom. I didn't realize that if a friend likes/comments on something you post that friends of the friend can then see the post. Once I learned that I then put all of those "mutual friends" on my restricted list, so that they can no longer see any of my posts or pictures. However, i recently found out that one of these "mutual friends" is very sympathetic to nephew's mom (obviously doesn't know anything other than what nephew's mom has told her). So because she is also a friend of other friends, she can see stuff that I post if those other friends like/comment on them. Which means she can pass any comments/pictures on to nephew's mom. Ever since I found that out, I haven't posted anything. I don't really know what to do. Unfriending the "mutual friends" doesn't do any good because many other "friends" have also friended these people. So the same problem applies ... if a friend likes/comments on my stuff then these "friends" of nephew's mom will be able to see it. And I can't ask all of the family to unfriend anyone who's friends with nephew's mom. Why oh why doesn't have a privacy checkbox that says I ONLY WANT MY STUFF TO BE SHARED WITH PEOPLE I FRIEND AND NO ONE ELSE!!!!! I have gone through the privacy settings many times and don't see any way I can prevent friends of friends from seeing content that my "friend" has liked/commented. Technically I could block the "mutual" friends but then I'd have to keep checking to see if any other "mutual" friends ended up cropping up down the road. We're waiting to hear back on ruling from TPR trial, if TPR is granted then we will adopt and we will definitely want to be sharing more stuff at that point. I guess my other option is to start using Google Plus instead, but most people don't use it. any suggestions? :(