What do you do when your roommate wants to help out with chores, and eventually gets around to them, but after about 3 weeks?

In contrast, I do my portion of chores about every 3 days (or once a week if it's something time-consuming).

I often end up doing her share of the work because I'm just not comfortable in a house that stays dirty for 3 weeks at a time.

FYI she has pretty bad executive dysfunction and deadlines stress her out.