Humanely killing the extras and then eating them sounds to me like a very good solution.Sounds to me like rabbits are too much work and she would rather snap their necks than deal with them after having three accidental litters.
That would avoid dealing with any more rude people on craigslist (or here), and would get the numbers back down to the original amount that was apparently right: TWO pet rabbits, with NO litters intended. And of course now she knows what gender her rabbits are, and what is needed to avoid any more oops litters (neuter/spay, with very secure cages until after the spay.)