Ask HN: How to leave a startup early (before equity cliff)?

My cofounder is waiting ~6 months to leave her current company until the 1-year cliff hits and she gets those shares. It could be crucial though to get her on-board sooner. What would you recommend? Are there ways to accelerate her vesting, buy out her shares, etc.? Yes my situation is slightly specific, but in general I hope this discussion is useful to others.