Step 19: Laundry Bicycle
Solution? Laundry bike!
She can wash her clothes in any sink, and then clothespin garments to the rear derailleurs cable to let it hang dry! It's summertime in Boston now, so the clothes dry out rather quickly, either by virtue of the fresh breeze while biking, or by being parked in the bright summer sunshine.
This works well for the "wear one pair of clothes per day, wash one pair of clothes per day", and can be incorporated into a daily showering routine.
Pants and shirt can be dried at the same time, each hanging over one side of the frame.