Are you crazy? Sanders supporters would never vote for a woman.
I really hope you're trolling. This is the exact same base Elizabeth Warren would've had if she had run, the same group that tried to draft her, and most of them still want her as VP (even if that's a fever dream).
Jill Stein definitely might turn this election to the Republicans, but I really think that the onus of the matter is on Hillary/was on Gore to draw in the left-wing voters. If they can't do that, it's their fault, not that of Nader/Stein.