In the dark of the night, a cloaked figure walks up to your wagon.
"Hello, strangers." she says. "I see you're going on a long trip. Can I come?"
She has her own dagger, and a cloak that keeps her from both frostbite and heatstroke (due to being black on the outside and white on the inside, reversable, the black soaks up any light there is and she's kept warm but in the day she reverses it and the white reflects more light).