really struggling with DD (7)

[rhetorician]

she was recently diagnosed with dyspraxia and some sensory stuff, and for the most part manages well. But I am really struggling with her behaviour at home which is rude, ungrateful and full of aggression (verbal mostly). In particular, she does things like try to make a den for the cat (who is 14 and very forbearing, but really not into it) and then gets angry when the cat won't do as she wants. When I tell her off she gets all aggressive, refuses to listen, and says things like "you like the cat more than you like me", because I won't let her mistreat the cat. I have just told her in no uncertain terms that she needs to sort out her behaviour and she is upstairs crying. If I even slightly raise my voice she stomps off complaining that I am being "angry" with her. I am really concerned about her response to being disciplined, and to her complete unwillingness to back off when asked, let alone when this is signalled more subtly. Ideas?

[Dellarobia]

She may be coming across as aggressive and defiant, but saying "you like the cat more than you like me" seems to me to indicate a sad, insecure child rather than a naughty one. Do you think she is struggling to cope with the diagnosis more than you realise?

[rhetorician]

she doesn't really know about the diagnosis as such - but yes, this is all insecurity - it might have something to do with the fact that I am going away for a week tomorrow. But I just don't know how to make her feel secure and happy - she sometimes makes mistakes because she is 7 and isn't the best at social situation, but I have to be able to tell her off!