You look at her and notice the skeptical look on her face.
You tell her that, in all fairness, you've been walking for a few days now, and last night you ran out of the last of your water. You were wondering if you could barter for a small resupply, just till you reach the next town. If she'd like, you could do work for supplies, if nothing you have interests her.
She asks you what exactly you have that you think she would want.