Really, the whole franchise has some of the best adoptive parents in any media. Lindy, Fate and Nanoha themselves, Genya Nakajima (who gets absolute top marks here), and I think we have to include Hayate, honestly. (Rinne's parents also seem to be good people, though her arc kinda depends on them not being great at parenting — pushing her abruptly into the rich girl school where she got bullied, and not tempering her cruel streak in her juvenile bloodsport career.) Heck, if I remember Triangle Hearts right (and that part is still semi-canon), I think Miyuki is technically adopted (she's supposedly the dad's sister's daughter) and Momoka is Kyouya's stepmom, so adoptive all around. One of the themes of the whole series is that you can choose your family.
I really do love the part early on in A's when Chrono is expositing about what's known of the Wolkenritter, and Fate's response is, "Artificial people? Ah, so they're like me." Chrono and Lindy immediately fall all over themselves to reassure Fate that she's real, which is great, and it also sets up how created doesn't mean fake for them, either.
