Hi Fuzzy, sounds to me like she's trying to avoid/avoiding feeling guilt/thinking about what she "shoulda, coulda, didn't do".
But maybe that could be part of her grieving process too.........looking for answers, looking for something/someone to blame...........
But whatever there's NO excuses for saying that to you, NONE at all!! So please don't shoulder any blame, that isn't yours to shoulder. This isn't your fault.
Sadly there are going to be people like your aunt in the world, but there are truly caring one's too e.g. plenty on here!!! So attention on "being with" them, hey??
That's where you belong!!!

Alison