I actually don't think she'll be angry with Tracey, actually. She'll see it as her very good friend being misguided and taken in by that evil Mudblood. Poor thing. So all her wrath will be for Stephen.
Her mind is a slightly disturbing place. I'm almost afraid of her.
Mandy would very much like for someone to cast a memory charm on her and make her forget that VERY EMBARASSING MOMENT. So she likes to pretend it didn't happen (whole privately moaning about why doesn't he want her). GOOD TIMES ALL AROUND.
Daphne I think will consider Theo one of her genuinely closest friends. He's probably the closest she has come to trusting another human being since The Incident She Refuses To Speak Of. I think she will be okay with him and Astoria so long as she doesn't lose any part of her friendship with him in the process, but she may feel a little replaced, too. OMG SHE DOESN'T EVEN MAKE SENSE TO ME XHUSHAHHD BUT I AM SO EXCITED TO PLAY HER.