Need ideas please

So my 3 year old is currently in therapy.. (long story )and will b doing speech this week.. Anyways the therapist noticed that when she plays or whatever she does when you ask her to stop or not to do something she don't she has a hard time ... Like for example say she playing with her step brothers if they stop playing with her she won't stop nor listen and nothing we have done has worked .. i.e. Time out yelling spanking taking toys/tv away.. Nothing seems to get thru to her.. She gets aggressive because she not very verbal so she turns to hitting.. A few weeks ago she was laying on the couch with her step brother and they were playing and she accidently kicked him.. He got mad went upstairs and then came back sat down next to her she apologized and he threw her off the couch where she hit her head on the floor.. Yet she is blamed for everything... Funny thing is whenever she plays and doesn't stop she gets hurt but also in trouble ......any other ideas... Everything from past parenting classes I've tried to input in her but it's like nothing works..her brothers don't want to come over that much and blame her even tho I've seen them intaganize her ...for example like today my daughter sat on my bed and the oldest boy started to tell her to stop and get off when she did nothing so I told him to leave her alone and he yelled at me so he went into timeout.. And I called my husband.. I'm out of ideas..I'm looking for ideas on what I can do to help my 3 year old..