She only has four slots, one is the future (probably around 16?18? Years old) which she uses to fact check largely recorded future events, one is the past, one of her earliest saves where she knows for a fact the her 'uncle' is still alive and she has ample time to make a plan to save him.
Than the final two are ones she uses as quick save slots, to quickly jump between two different possibilities. (Important.)
She's auctally insanely smart to be using them like that, she simply didn't have enough save slots to keep it and try.
She could've indeed overwritten her earliest save since it hadn't even been a year since that point in that current timeline, but she said it herself TOO much had changed, her actions changed too much that it was too risky to do that. She really really wanted too, but the risk was too great, she had altered far too much in that timeline already to make it her oldest save point.
But still i wish she save the part where her bio dad want to be her father
Why didn't accept it if dhe didn't accept it she can just keep it as save point just incase something went wrong