I dunno, I kinda like that it was so sudden? She made e the decision very suddenly but it's not like it hasn't been building toward that. But also consider that his chapter is primarily from the husband and friends' perspectives, of course it's going to seem very sudden to them, especially the one friend who's freaking out because he had absolutely no idea about all of the stuff that we the readers know and what the husband has picked up on. I get why people might not like it but I think it conveys what this would be like for everyone fairly well. They could still revisit her decision in the final chapter of course but I don't really think it's needed.