Pushing Buttons

I need some advice on how to deal with a 3 y/o dcg who is constantly pushing buttons with everyone, myself and the other children. She seems to like the reaction she gets when she gets in the other kids faces and constantly pushes or pokes or shoves with her belly. Time outs only work for a little bit, then she goes back to trying to annoy the other kids. I've tried removing her from the situation and giving her another task to do, that works until we come back as a group again. I cannot keep her segregated all day. It also doesn't help matters that one of my dcb (4.5) is über-sensitive and is easily bothered, so she goes straight for him each time. I've tried telling him to walk away, don't react, don't talk to her, but he can't help himself.
I've had her in my care for over a year and this behaviour has been escalating in the last couple of months. I believe it's partly because dcp both work odd hours and somedays dog goes straight from dc to a babysitters care at home. I know itMs attention seeking behaviour, but I can't let her keep pestering the others and have to remove her. I am trying to give her more positive attention when she is behaving, but I'm not sure it's enough. Thoughts?

Why can't you segregate her all day? She is being annoying to the other children so I would make her sit with some quiet toys, ie puzzles, coloring, or whatever for a period of time. Allow her to go back and if she repeats the behavior back she goes. If a child chose to sit and color or sit with me all day instead of playing it would be fine, so you are just making that decision for her. It probably won't take long for her to figure out that if she isn't nice she won't be welcome to join the group. This has worked for me in the past. I am not being "mean" but can not allow one child to dominate the others.

I so agree with madmom, i would have her segregated from the group until her behaviour improved, if she has to go back and forth from the group to her little spot 100 times, so be it, just make sure u shadow her so u can act quickly, u will see in time you will not have to shadow her behaviour as much, good luck be consistance.

also i wouldnt make it into a chat session with her either, keep it simple , this is just a side distraction she will use hoping u forget she's going to her little spot . lol