I'm not sure how many children this woman is watching, or if she is a solitary chaperone on a field trip, but since there are a lot of them, I am going to assume that every kid on the train is hers.
She is younger than me for certain and quite attractive, but possesses a store of the wisdom of motherhood.
She look calm, tired, but vigilant. Every child around her is very well behaved. When they do act up, they look over at her and stop immediately. She smiles at them with her mouth, but not her eyes.
If she told me to sit up straight, I probably would.
In the interest of protecting the innocent, here's a picture of her foot. =P