This is not a good book, merely OK at best. The plot moves along at a good clip, but there's a cheat at the end because the big bad ends up being someone we had no way of guessing as there were absolutely no clues. As a matter of fact, the big bad is unbelievable as his identity comes out of nowhere.
The other problem is, the plot hinges on the daughter making a decision based on reasoning that doesn't fit at all with the characters' interactions. She really thinks her mother is going to get upset about her presence at a party when nothing else she does seems to get her mother riled up? She really thinks her mother is going to care about her presence at a party when daughter can ID the killer?
And the writing. Oh, my word, the writing is just not good. The author appears to be worried that she might be considered a genre hack for writing what might be considered a murder mystery and so devotes herself to larding the story with countless metaphors that add nothing but bulk. As an example, in describing fall leaves, the author writes, " ... crazy reds, headstrong yellows ...." What on earth does a shade of yellow have to do to be considered headstrong? Does it have to go to a party its mother disapproves of?
It's too bad the author had such literary pretensions as this could have been a good book if she'd had more self-respect and a better editor.