It depends on the strain. It looks like you lucked out. Generally a long night plant requires 12 hours of darkness to maintain flowers, and 24 hours will cause the plant to revert to vegetative. I have used unorthodox cycles, such as 24 hours on, 12 hours off,
but only for a few weeks, to push the plant to produce more weight. Even this will risk stressing the plant, and putting out a few male flowers, or you might be surprized one day to check your garden and be greeted by a mass of male blooms on your female plant. The seeds will of course all produce female plants, if it really is a female mother, and not a hermie. So you struck the jackpot. When you harvest her, see if you can cut it back to a few branches, put it under a blue rich light, like 6500k fluorescent, or even a blue rich metal halide, to try to get it to revert to vegetative, and take cuttings.