My daughter detached from me in a frightening way when she was Miss A's age. She wasn't my little girl any more, and had even moved into the basement bedroom for independence and privacy. My attempts at setting boundaries and offering guidance were hindered by my husband not wanting to "make her mad." Thankfully, one of her middle school teachers spoke to both her dad and me, stating that daughter couldn't handle the amount of independence and freedom she was demanding. That advice seemed to make an impact with husband, and we promptly moved her back upstairs to her old bedroom. (He wouldn't have listened if I had suggested it on my own, but the teacher actually told us that should be the first step.)
As a middle school teacher myself, I do think boundaries are necessary at this tender age. Limited use of the Internet seems to be called for in this case.
Also, we don't know enough about the parents, particularly the mom, to condemn her. It sounds to me as if she truly loves Miss A, and is trying.
Seeker