Hi Kathye,
I agree with all that has been said so far, but have to add that 12 weeks is a little long to leave the female kit with the Dad I think.
You can leave a female kit with Mom for life, but most of us take the kits out at 8 weeks.
It's not common but a female kit could start heats at 12 weeks, and I would think it a bit late for Dad to still be with her.She couldn't deliver safely so I wouldn't chance it.Some of the more experienced may feel different, but I like to be safe
If you have their papers and are planning to breed, you can never have too many cages, and will always need a spare.
Remember you'll only get kits, as healthy as the lines you use, so to get the best, breed the best. Things will go wrong anyway, we try to help new breeders avoid some of the hearts aches, and the loss of beloved pets.
Oh and fingers are a common loss when chins don't get along. If they can reach each other cages, or a cage can be reached while they are out side, they will chop them off each other.They usually heal up just fine with your basic first aid.
What books do you have?