Questions, hope someone can answer

Howdy all. I have 2 questions, #1. how long does it take to see if a plant has been fertilized? a buddy has about 14 plants (all different "ages", and after picking a bud, and checking it out, it was somehow fertilized, and full of seeds. his problem is that he lost track of how long they had been in the bud room, and was guessing the age of that one at 9 weeks (in flowering stage). three days previous to this he harvested 2 smaller plants (8 weeks old) and perfect buds. tonight he pulled out 2 more plants, ond they were both fertilized, and there was a small open flower on one of them (that had fallen onto a leaf - is the only way you could tell), but there must have been a hermie there somewhere, as all his plants are female, and have buds, and hairs, and the fact that they are fertilized (some) came as a complete suprise. he also has a problem with powdery mildew, and cant tell if theres pollen on plants, or powdery mildew. What are the chances all the rest of his plants are ruined (fertilized) and how & when can you tell if they are, and anyone know if theres a good way to get rid of powdery mildew???? most of the plants left in the room have been there for 2 weeks, 3 weeks and 4 weeks. - and he has big bud x northern lights (which were the only ones grown from seed, and, the only ones ordered from the internet.) the rest are northern light x skunk #1, jack herer, whiote rhino, and blueberry rhino. the Big Bud x Northern lights, when grown from 10 seeds, yielded 1 female, 3 fertilized females, and 6 males, is it possible the seeds are hermie, and/or are they even usable, or was it a HUGE waste????

hope it wasnt a huge waste

Are you talking about pollinated? A plant can die within a day due to overfertilization. It takes a seed about 5 weeks to completely ripen. chances are if there were no males they would be feminized seeds with a chance of turning hermaphrodite. Dry the seeds out for a month before attempting germination. I will take the seeds if you dont want them.