Keep the male separate from the female from now on, not just a week. If you put him back with the female they can end up breeding again, being pregnant again while still raising a kit is hard on the mother and gives her no time to recover, which can kill her. If the kit is male it can often end up living with the father once it's weaned, otherwise the male may need to live alone. If the kit is female it can normally stay with the mother for life. The other option if you want them to beable to go back together (especially if the kit is female and you want them all to live together) would be to have the male neutered. It's risky and does come with a real chance of things going wrong during or after the surgery and him dying so you want a vet that is very experienced with chinchillas to do it. If he survives, and there are no complications that extend the recovery, after 8 weeks he can be reintroduced to the female and the kit.