Your mama seemed like she really cared about you and she would have been great to talk about anime with. it's very difficult losing a family member that you loved and cared about so deeply. I hope the last few days of this year are better for you and thank you for your hard work!
She'd been with him for a long time, I think she'd gotten tired of the caution, she didn't want to live in fear of his venom like he has always been. I don't think she wanted to die, but was just reckless. Maybe his over caution, made her think that it wouldn't happen. Who knows.
having read the novel now, I like the manga more. It makes me realize how much shit she goes through and what is most important to her. I really like her as a character, considering how fucked up the world she lives in now. I also really like how her relationships with reoccurring characters...
I'm guessing every single capture target is crazy in some way. I think easy mode just didn't show how crazy they were vs hard mode you get to see how crazy they actually are. Tough choice on her part.