Makes me wonder if your mom is somehow also my mom. She's always said weird things like that. People have offhand said behind her back that she is (or "was") brilliant and "could have been anything" if she wasn't the way she is, which is not human on the inside. Thank god she wasn't anything important. You wouldn't want a surgeon or a physicist with no human feelings.
I think she survived by becoming what she is, but perhaps she already, naturally, had some kind of tendency to be like that. I think I survived by having a talent for observation and simultaneously masking what I observe. Don't let the monster know you know what it is.
It's tempting for nice people to see the terrible things that have happened to other people, especially their family, and give them behavioral allowances because of what they have suffered. If my mom said to me what your mom said to you (which she would), I would probably not reply. She's talked to me like that before and I've calmly laid her out, been like, what a f***ed up thing to say, do you realize you sound like a villain from a story? It would intrigue her to be intellectually debated. She would also enjoy if I replied with shock. When I ignore her, I take away her fun. I don't fool myself into thinking that she is truly trying to "help" me with suggestions or comments. I would be surprised if your mom was either.