I have been desperately trying to remember a book that I read in 2006 or a couple of years before. It was a women's thriller, and I can't remember what it was called or who it was by.
It was about two mums, Mum A who was confident and carefree and had two children who may or may not have been called Scarlet and Laurence, and Mum B who was anxious and shy and needy and had two children who may or may not have been called Poppy and Joshua. The mums became friends because Mum A felt sorry for Mum B, who became incredibly clingy and stifling, and Mum A tried to wriggle free. Their lives became intermeshed and the book ends with one of the mums killing the other, and they leave it deliberately unclear as to which it was, and one of the Dads (married to Mum B, a bland guy who may have been called Graham) raises all four children. I keep thinking about it and I'd really like to reread it. Any clues?
The only other detail I remember is that the women get drunk and share a kiss one night but are definitely straight.
I asked Google and AI and have ruled out all the authors it suggested! Not Ruth Rendell, Barbara Vine, Nicci French, Marsha Ward, Jane Green, Adele Parks...
Very grateful if anyone can help!