What I meant was that there was no reason for her to kill herself in order to help Harry. When I read your previous comment:

I'm not sure it was such a trick. She could have killed herself

I didn't parse to mean "Voldemort bargained with her to make sure she didn't kill herself, so he could kill her instead". But yes, that's a plausible interpretation, if victims of Voldemort sometimes killed themselves for any of the reasons you give.

When does Voldemort ever linger at the scene of a crime for multiple hours? I'm fairly sure that would violate some Rule or other. No, simpler if the plan fails to fallback to killing Harry directly and making a timely retreat as a dark lord should.

He needn't linger there; he could just take Harry and leave with him. Before he created the Horcrux, Harry had no particular protection from Voldemort.