Alex: This should work, I think. White should back down and play at a or thereabouts with and let Black make two eyes. If she stubbornly tries to kill...
Yeah, that works. In the real game the situation below was a little more complex, such that was big sente in that a White stone at a killed either or ; this has nasty consequence for my right side. I'll update the problem to reflect this...
LukeNine45: At first I thought about Alex's solution, but what if white resists like below. I think black can still get a seki?