Hmm, I don't know. I think I would buy an interpretation of Alys as Gryffindor (certainly in a lot of fic where we get to see more of her, she's portrayed that way) and it's not that she's not brave (or manipulative, or hardworking) but her specific canon talents are all about knowing things - she knows fashion, she knows protocol, she knows social history and tradition and law, she knows aesthetics, she knows everyone who's relevant to Barrayaran power and all of their interconnecting relationships, she knows exactly how far she can push things and she knows how to build effective strategies for quiet long-term change - and she's happy doing all those things while being underestimated in the background in a blue-and-silver dress! The things she knows are women's sphere things, too, but it takes just as much intelligence and learning to know them and apply them.

(ETA: Ekaterin, on the other hand, is Gryffindor to the bone. She's all bravery.)