L.T.
It's very unfortunate that this child is treated like such a burden. She obviously needs a mommy figure to nurture her and be patient with her. Have you spoken with her mother? This is obviously an unhealthy situation and maybe child services should be notified. At the very least they could demand that parenting classes be taken. As far as the pace, what's normal? They may be the child's way of getting the attention she seeks. In a child's mind, negative attention is better than none at all. Not that I think that giving her negative attention is the answer but it's apparent that this baby needs nurturing.