KK has it right with kitchen steward, you're inside and relatively warm for the majority of the day. Sure, as a maester or maester's steward you get to read and spend quite a bit of time inside, but mother eff those birds and their constant noise/shitting everywhere.
Also, I don't think the bastard's inheriting lordship thing started happening until the war of the three kings.
Sansa is my least favorite character at the moment, she sucks.