Give her the positive attention she is seeking, you say you have a 2 year old and as you took her away to 'get away" from him I am assuming there could be some jealousy issues and she sees her brother get most of the attention at home, Understandable as he is only 2, instead of demanding she listen and be attentive, do things with her at home , and make sure they are fun things, board games are a lot of fun and the 2 year old is too young for them so it could be the 2 or 3 of you perhaps when the younger one is napping,When the boyfriend is around get some outside activities going maybe he will play ball with her so she gets his attention also. When she has an 'attitude: say nothing dont feed into it she has learned that she gets negative attention which is better than none so ignore her behavior,if she isnt getting any reaction maybe she will stop.