Ask HN: How do I resign as an unpaid Co-founder?

I joined someone in a startup 4 months ago and quickly realized I made a big mistake. And not having worked closely with her before (we were not close friends, but did know each other from around) I found many, many things that turned me off: her poor work ethic (consistently 1-2 hours late to our agreed upon start each morning, giving all matters of excuses, also lack of focus throughout the day), her dishonesty with potential customers and investors (saying someone is invested or advising when they're not), her general lack of business and sales sense, her lack of direction and focus on a strategy or target market. I could go on and on.

I want to leave this situation asap. But as an unpaid co-founder only 4 months in, is it still customary to give 2 weeks notice? Should I work unpaid for another 2 weeks? If not, should it be hourly or pro-rated based on the future salary we are supposed to take after investment? Due to the kind of person I think she is I believe theres risk in not getting paid for those 2 weeks even if we agree to it (we do have a tiny seed investment that could cover it with leftover).

What have other unlucky folks done in this situation?