My daughter is fourteen and was diagnosed with ADHD when she was seven. She has outgrown a lot of her ADHD except for her impulsiveness. She seems to do things with no thought to the outcome of her actions. She will deliberately withhold a toy from her little brother(he's four) so that he will cry; she will hit him behind my back and make him cry(he's learning to hit back).I don't actually see the hit, so I can't be 100 percent sure(but I know this is what she is doing). How do I handle her behavior and keep from teaching the wrong thing to my son? She constantly pushes people's buttons that she knows will get them upset with her, then she whines that no one likes her. I'm at a total loss with how to deal with her.
First, I wouldn't assume her present behavior is just some left over ADHD that didn't go away. She is, after all, 14 and her behavior is not inconsistent with how many teens her age act with their younger siblings or in general. Sometimes we do what we're good at, even if it always gets us in trouble, like pushing people's buttons. She hasn't learned positive ways to relate to her little that bring her the attention and/or confirmation that she gets from doing these nasty things. At this turbulent time in her life she may not think she's pretty enough, smart enough, athletic enough, popular enough, cool enough to be well liked by her peers; when you're this age that tends to be how you measure "having a life".
Why don't you tell her you miss spending time alone with her (believe it or not she may have felt and may still feel "replaced" by her little brother as the one who got most/all the attention in the family) and see if she'll warm to the notion of having a regular or semi-regular time out with you, like Saturday breakfast out. She may do it and appear like she's doing you a favor; ignore the attitude, she can't help herself. During these times out you may be able to reconnect and have some talks that allow you to sympathize with the things that are going on in her life. During these talks you can say things like, "I know you don't want to hurt your brother's feelings like you do; I know it can be rough having a little brother around." Check out Faber and Mazlish's book" Siblings Without Rivalry" for some good examples of how to talk with her about her relationship with her brother.
She's telling you her life SUCKS and wants you to pay attention to that. During these teen years sometimes the best we can do is "name the pain" they're going through and offer some thoughtful, sensitive, supportive words. They may tell us we're all wet but down deep they need us to abide with them and love them more than they need us to have all the answers. Good luck.