Ultimately I think this is yet another of the problems/issues created by the multitudes of drafts getting redone and reduced over and over before finally becoming a simple lower budget filmable narrative that was then retconned and further complicated by the plot twists in the sequels that then undermined the story of the first film. The EU made attempts to define some of these which are now out so again we’re back at square one.

Soooo…I’m just going to stick with the adoptive parents who may or may not actually be blood relatives.
As a kid I often wondered how in the hell would Vader not recognize his only relatives suddenly have offspring and could only surmise that there was some pain inherent to his character that would make Tatooine the last place he would ever go…yet Vader seemingly has no restrictions or memory of anything in SW because the character shift didn’t exist yet…isn’t the inconsistent retconning fun? 😉