Immature 17 year old stepdaughter
I am recently remarried. My husband has two daughters. Both have been tremendously sheltered, which isn't a bad thing. The 16 year old is a little immature, but the 17 year old has ADD (she takes medicine for it) and acts more like an 11 or 12 year old. Other kids her age don't want to be around her; she is very impulsive and can't seem to control her behavior. She drives my friends' children close to her age crazy with her needy, extremely immature behavior. It is obvious to everyone outside the family (and some in the family) that she has major problems. The difficulty is that neither of her parents, nor her grandparents, will acknowledge that she has any significant problems. I have raised a child with Down syndrome, who is now 22, and I think that there is something more wrong with this 17 year old than ADD, but my husband acts like I'm crazy if I mention it. She is a senior in high school, but has very few friends her age, and is rarely asked to do anything or go anywhere. I want my husband to notice and point out inappropriate behavior to her so it can be corrected, but it may be too late for that??? I have consistently done this with my Down's daughter so that her behavior in public is socially appropriate. I am at a loss as to how to deal with his 17 year old. She refuses to do anything we ask her to do when she is at our house, saying "she doesn't know how." Trying to show her how to do something is equally frustrating, and usually ends with tears so she won't have to do it. She is often disrepectful to me, but acts like she doesn't know what she has done on the occasions when her dad confronts her (and he usually believes her). I don't want this to become more of a wedge between us than it already is. I also want to help her mature and develop socially acceptable behavior so she can have friends and act appropriately in group settings.
Any advice would be greatly appreciated.