I'm speculating here, but I'm guessing that when she took the job, she thought "Sure, this'll be a cinch. I get a full salary, and if it works out, a nice bonus." Then it turned out the job was much harder than she expected, she saw the founder with 94% doing basically nothing, and said "Dude, if I'm going to slave away with this code for months, I should get founder-level shares. Otherwise, I could just do what you're doing and take the 94% you're getting" and tried to renegotiate for a stake that'd make the development pain worthwhile. The OP refused, so she walked.

Chalk it up to first-time founder mistakes on both sides. Almost everybody drastically underestimates the amount of effort required to get a startup off the ground. So what seems acceptable at first ("yeah, this won't be hard for me, I can whip it off for you") starts to feel like you're getting massively ripped off later.

And I totally agree with the comments on other subthreads that she's probably not a very good Django dev. I wouldn't be surprised if this is her first Django project. I remember that I expected my first PHP project to take 3 months; it ended up taking 3 years (I didn't charge for it; it was a volunteer project in college).