Hi I have 4 girls, the oldest is 9 second oldest is 6, then I have a 2 year old and 1 year old. My 2 year old is violent with all of the other girls. Especially the 1 year old, she is jealous and I she has a speech therapist because she wasn't talking much. Tho she is talking more now, we try to get her to be nice to her sisters but she runs off crying. She may not know the words to express her feelings but I work with her everyday and she stopped biting. I want to know if anyone has any ideas about getting her to be nicer. She does love her sisters especially her baby sis because she doesn't want any strangers touching her or never wants to leave her, and I don't understand why she is so mean to her. I'm doing everything I can think of, spending time with her, showing her I lover her and her sisters, I play little games with her. I need sum advice

My friend daughter was like this she receive help by going to a counselor and being firm with her at home, not beating, but firm talk and punsihment. It worked for her 2 year old.

Has she been evaluated by another professional to make sure her behavioral problem isn't anything more than the "terrible twos"?

If she has, the solution is in consistency, persistence and patience.
It seems like you are trying and doing the best you know how so I'll only make suggestions you've probably tried:

You have to stop her violent actions every time... I work with kids in this age group and find it most effective when I actually walk up to the child and get down to their level to stop them (to be sure I have their attention). I say "No" or "No hitting" very simple they don't need a lecture or anything at this age then the next time they repeat that act discipline is implemented (time out or whatever works for you and your daughter).

The next thing is to catch her being nice and loving to her sisters and praise this behavior! Encourage the behavior you want to see her exhibiting, naturally she'll want this positive attention instead of punishment.

Just stay consistent and persistent don't allow any bad behavior to slide and always praise good behavior. Hopefully with patience this hard work will pay off!

I still wonder if her speech deficit is linked to some other disorder that may be the cause of this undesirable behavior.