No. Females should not be housed with a male until they reach a proper breeding weight. The prescence of a male can stimulate young females to produce eggs early, and you'd be surprised at how young some males begin trying to mate.
No. Each gecko should be housed separately for 3 or more months to quarantine and avoid any disease being spread. Also, a six month old male could be ready to breed (and if he is, he will try every chance he gets. Think "Horny teenager".), more than likely the 6 month old females bodies are NOT ready to handle the stresses of reproducing/egg laying. Breeding now would be a M|A|J|O|R health risk to your females.