I asked her if she'd be ok if I was a boy and she said yeah. But when I told her my chosen make it took her forever to get used to it but also she still thinks if me as my deadname like almost 7 years later. My dad is dead and he's always been more understanding of that sort of thing and my mom and I have a strained relationship. Like she's not transphobic per se but I don't think she understands the epistemic framework that makes it so she sees trans people as their chosen gender. It's complicated. I don't think she'd ever mistreat me for being trans but I also don't think she'd like outright defend me for it. It's complicated.
Like she's not hostile towards trans people but she's also not understanding of how being trans works or comfortable with me being different.
She could be ignorant (perhaps not the right word) and still be accepting. Which is how any parent should be.
I will admit that I do not fully understand because I personally am not trans (I mean no disrespect). I understand however that this is who you are which is something you didn't choose, your only choice is what to do with the life you are given. I accept and support you. So perhaps she would feel as I do. And I certainly hope that is the case.
If I come across as cautious, its because while I have no experience, I realize that trans people get treated poorly. And you don't deserve that as you have done nothing wrong. You are as important and unique as anyone else. I'd like to see you be supported and be able to find happiness. And I do truly hope that can happen for you.
Ask yourself what you want from telling her. If it is acceptance, you may get that. I'm thinking if she was ok with your line of crumb trails, that she may meet you half way in this. Perhaps it may open a path forward for you.
I truly wish you the best. I can only ask that you take the time to think about your options. If ctb is your choice, inform yourself before making any permanent decisions. Rash decisions don't tend to end well.
Be safe my friend.
P.S. sorry for my late reply, I'm not always around as I try to keep this low key.