could go one of two ways:
Either a personal companion type thing, where we have a meeting of minds and stimulate each other in that sense, in which case she needs to be quick minded, thick skinned, adventurous, broad-minded, intelligent and cultured, laid-back and unmaterialistic. Then we'd look to each other for fulfilling conversation and counsel and feedback on the things we do when we're apart, whilst we'd be looking to platonic friends more for the life direction type stuff.
Or more a team mate kinda thing, where we get our most satisfying conversations with platonic friends and don't look to each other for that necessarily, but more as parts of a team working towards a common goal of where we want our lives to take us, in which case she'd need to still be thick-skinned and adventurous, but the other stuff above becomes less important, replaced by things like reliable, dependable, nurturing, hard working and motivated, practical and possibly even a little ambitious.
Either way she'd have to NOT have a psychotic family that I'd be expected to become part of. In fact, either way, she'd have to remember I'm marrying her, not her family, and that I will never see her parents as anything more than "people I met", purely for her sake. I might end up liking them and getting on with them and seeing them as friends, but if I don't, I'm not going to ever be attached to them or willing to drop things I wanna do for them or spend Sundays at the dinner table with them, etc etc.; she's likewise absolved from those kinds of things with my family, too.
As for appearance... well, as long as she don't stink, I couldn't care less really. Honestly.