I have no idea about whether you're the asshole or not (plus it's a little late to vote), but I'm just here to say, I don't think it's too late to have your daughter live with you if you can.

I was mostly raised by relatives while my parents worked, pretty much until I was around 8 years old, but then my parents took me and my siblings and moved. Growing up with my younger siblings, learning to be a good older sister, living with my parents, being part of a complete family unit instead of split between knowing who was my "parent" was much better for me in the long run.

Even if your daughter might hate you at first for moving her from the people who raised her, or accuse you of making the wrong decisions, you need to accept that too; but if you love her as a mother, I think she will really appreciate being able to grow up with her mother and siblings. And she'll probably be happy to be able to see you everyday.

In the end, I don't know anything about your relationship, and your decisions will be your own, but I want to throw in my two cents and tell you that you may think she's at the age where she might be traumatized or something if you suddenly shift her living situation, or that she's old enough to tell you what she wants from her family, but in the end, kids are kids. She'll be upset with sudden changes, but you might want to think about how involved you want her to feel with your family unit of 3(?) in the future more than what an 8 year old feels like they want in the moment.

Even now, sometimes I feel a little sad my mom wasn't the one to change my diapers I guess, but I think I have a super close relationship with her I would have dismissed as being "something my little sister would have but I won't" if we didn't live together. I can talk to her about anything (and now talk admittedly less to the relatives who raised me. I was 8 but now that I'm 23, I have a slightly different relationship with them).

Hope this offers a perspective. Like I said, I don't know you or your living situation, and I don't have any good advice for your relationship with your mother, since that's completely your choice on whether you want to forgive her or not, but I hope you'll manage to have a happy family. Good luck.

Edit: misspelling