1 Work in Het, Not Straight
The life of a Grey Warden is one of terrible sacrifice. Everyone knows that, even if they don't know exactly what it entails. But no matter how violent and dangerous it is, it has to be better than the terror, persecution, and abject misery of Kirkwall's Circle of Magi. Killing darkspawn sounds preferable to killing herself, so when Scarlet's twin sister, Rose, appears out of nowhere with a couple of Grey Wardens and the Right of Conscription, she doesn't ask questions.
When backed into a corner, it's been said, mages have options that other people don't.
[Spoilers for Dragon Age II. I attempted canon compliance (except where canon is fuzzy, or canon and I disagree about how difficult and painful magical healing should be), but I'm only human.]