Quote from kesvalk:
old bird wasn't her father figure, it was more of a master than a father...
my god, he is a giant inteligent chicken!
no way in hell samus would see him as her father...
my god, he is a giant inteligent chicken!
no way in hell samus would see him as her father...
Only thing I can think of is that while Old Bird and Gray Voice were important to her, they're not exactly human now, are they? Adam is the first of her own species that she sees as a father figure other than her own father who she knew for only three years when she was young. Entirely different personalities and mindsets between Chozo and Humans, and the fact that Samus is essentially part of both parties probably didn't help her very much to try and fit in and be accepted by either.
Eh, maybe not the best explanation, but I'm kinda speculating here. Other stories have done it before.