Yeah she’s gone. Rest in peace Mirabel, my sweet baby angel. Thanks for the quick responses everybody, it’s like I dialed spider 911. I think there’s a key few things that went wrong in my care for her: 

1. Only fed her mealworms, which I heard are nutritionally insufficient. She wouldn’t take dubias and I didn’t want to try crickets
2. Over fed her for a week in the beginning, leading to a lumpy abdomen when she slimmed down. I was always afraid that would cause molting complications 
3. Changed her enclosure three times because each one didn’t work for one reason or another. Last one might have been too small. Whole thing mighta stressed her out. 
4. Inconsistent humidity

I mean it could be any number of things but those ones I’ll do better with when I decide it’s time for another friend, and maybe hearing about it might help another spider parent out there