Following other people's lead and writing one for my own character: I kind of think Gert's a Gryffindor. She's smart, but the pursuit of knowledge definitely isn't what motivates her. She isn't sneaky or manipulative, and while she's loyal, she's certainly capable of yanking her loyalty back, too. What motivates her for the most is that she's passionate about causes, and I'd argue that she's the Gryffindoriest of the original Runaways based on how firmly she hangs on to her morals and how willing she is to up and leave her home like that.