Thanks for the detailed answer aevojoey.
Has this always been this way? I might misremember but i think in much older versions of whoremaster if a girl was completely mindbroken she also always obeyed.
Rebelliousness is set by House%, happiness, love, spirit, obedience and a couple other minor things.
A few traits can set rebel to a maximum number: Broken Will is -100, Mindfucked is -50, Dependant is -40, Retarded is -30, Meak is 20.
After rebel is calculated, job enjoyment, matrons and then the girls feelings toward you are added in.
Finally the result is compared to a random roll to see if the girl does her job.