7 year old constantly blames her naughty behaviour on other people. Help!

Hey parents, I'm at a real loss with how I can help/parent my daughter in regards to her acknowledging her own behaviour. She is going through a period of defiance. When asked to do something she doesn't listen, encourages her 4 yr old brother not to listen as well, she has been doing things she knows is wrong (attempting to unlock my phone when she knows it's not allowed) and a lot of 'your not the boss of me' comments along the way.When I speak with her and ask her why she is doing those things, ask if there is anything wrong etc. She always comes back with a blame on someone else.Tonight's example being she blamed her dad because 'he moves his hand away when I try and high five him and I don't like it' for the reason she didn't listen and continued to run up the hallway instead of brushing her teeth.It's extremely frustrating and I just don't know how to proceed. I want her to be more aware of her actions and understand that her behaviour is only determined by herself and not others. I've obviously said this to her multiple times but it just doesn't seem to be sinking in.Any tips or tricks? Is this a phase she will grow out of or something that really needs addressing. This parenting thing is hard sometimes and I really don't want to fuck it up.Thanks! via /r/Parenting http://bit.ly/2JOK3fh