Under certain situations (stress) a female plant can produce male pollen and self-pollinate. If your plant is a true hermie there should have been evidence of male and female flowers on the plant. It also would have pollinated any other females in flowering stage in close proximity to it. I would kill off any hermies if I were you. The seeds will carry the same hermie traits as the mother plant. I don't know about you but I put a lot of effort into my grows and the last thing I need is hermie seeds. I want BUDS! Potency of hermies are lower since once the female buds are pollinated the plant goes into seed production and THC isn't needed for producing seed.