I do have an aunt on my mother's side (half sister) and she converted to Christianity pretty hardcore back in 1963 and her and my mom never really recovered from that. I've tried to find out information from her before she's REALLY weird about everything, it's frustrating. She gave me a photo of my grandmother after my mom passed away in 2010 and told me she didn't want to hear from me again :/
I recently found out that my mother lied about her birth date, so that complicates things further (duplicate records, not sure which is actually her or someone with a similar name). I found her mom's obituary one time with her married name, but honestly after that it all falls apart. My grandmother ran away from her family at an early age and discarded her name, got married in the early 30s. Her first husband found out she was Jewish (my aunt said the antisemitism was very bad then so my grandmother hid it), divorced her, she met my grandfather and they got married before the war. My grandfather is equally a ghost, used a fake name and lied about his age to join the military, apparently this was super common back then.
I was told that I could get my mother's birth certificate in another 5 years (she passed away 5 years ago, since I'm out of state and my birth certificate has the incorrect birth date (because she wanted to appear younger :/) on it, I have to wait the full ten years) But my aunt told me that even if I find the "maiden name" my grandmother used on the birth certificate, it's probably false.
Sorry this was long, I am just at a bit of a loss. In a couple weeks I'll start getting familial matches over on 23andme and I'm hoping that'll give me some leads on her side. Everyone I know that's Jewish is deep in the yiddishkeit and teases me that I wasn't, but I came from a very weird family so I always just chalked it up to that.