You should take away anything that could be used as a nest box, try to shorten their days by making it dark longer than it is light. And of course the hardest chore of all, separate the girls from the boys. Another suggestion that has been made by another of our members is to stay with just fortified seed. When they have the abundance of special foods (greens, treats etc) it tells their bodies that it is breeding time.
Good luck, sounds like you have your hands full.
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Barbara