What legal action are you thinking he could take to force someone to work on a project? Even on consulting projects with defined statements of work and acceptance criteria, it is hard to recover up-front payments when projects go bad. This doesn't sound like a consulting gig; it sounds like an employment arrangement.

Also, bear in mind that if he structured the company as an LLC, there's no such thing as an equity-holding employee; she's a principal. He may not even be able to fire her or recover the equity, unless they're on good terms.