Or rather, should Power Girl be Clark's actual IN universe cousin, and Supergirl is a clone of her similar to Superboy, but with genetic memory and thus THINKS she's actually the original? I mean Kryptonians, generally, WERE kinda cloned anyway so this doesn't change much if anything.

I say it kills two birds with one stone. After all, different personalities and characters or not.... They're still essentially the same person from a different universe already so pretty much still clones. 0_o

Na, I like Power Girl being a refugee from another universe (until DC ruined her with the new 52) and not knowing her place in the main DCU because Supergirl exists there.