That what makes no sense.
Why use a name all of sudden that you never liked/used because some dudes that tryed to manipulate you choose it ?
She now loves her dad because she mind wiped him ?
THAT is what makes her choose the random paper name over the one she identify as for YEARS ?
This makes absolutly no sense.
It's not all of a sudden.
Mary Sue Poots was the name the system gave her and she hated it.
Skye was the name she chose herself but it was just one of her many aliases.
Daisy is the name she never knew her parents gave her, and now that she does, she knows that she wasn't given away or wasn't wanted but that her parents loved her so much they went mad when they lost her.
It may have been for just a little while, but the time she spent at Afterlife, having dinner with her parents - that's all she wanted her entire life, to have a family and know the love of her parents.
That's why she has decided to use the name. It's not sudden or inhuman (hehehe), it's natural.