Sam,
I agree with Bright Eyed that you need to start doing a LOT of research. But for the sake of expediency I will try to list everything you need to do in the immediate future:
For Dad: Separate him from mom. You will need to get a second cage for him, which I would keep nearby mom, but at least 6 inches away, so they cannot mate again, if they haven't already. Female chins go into heat immediately after giving birth, so she is likely already pregnant again, but it is good to separate them to be careful.
For Mom:
1) You need to feel her belly and make sure it is soft. If her stomach feels hard or has any lumps inside she needs to see a vet ASAP, as it is possible she has a third kit (dead) or the afterbirth still inside, and get a serious and life-threatening infection. Also, check her vulva to make sure she is not still bleeding from a tear.
2) Give her a second water bottle on her cage with 50/50 water and either cranberry or apple juice. Make sure you get the kind with no sugar added. This will encourage water consumption which will help her produce enough milk for her babies.
3) Get yourself a kitchen scale that measures in grams, as Bright Eyed said. Weigh mom every day and make sure she is maintaining her weight. Also, please list her weight on here, so we know if she has any additional needs.
Being so young, I would recommend a supplement, as she is still growing herself, and her body is trying to support her babies as well. CA Chins website has a good supplement recipe, and maybe some of the other members here could tell you what they use. I would provide at the least some cuttlebone, and add some calf manna to her food, to make sure she gets enough calcium. Too little calcium can cause hypocalcemia, which can lead to seizures, and can be life-threatening.
4) DO NOT let mom take a dust bath for at least the next week. Her vulva will remain open from the delivery for a time, and allowing her to bathe too soon can lead to infection.
For the kits:
1) Weigh them and post their weights on here. You should weigh them twice a day for the next couple of days to see how they are holding their weight. A normal healthy kit will weigh somewhere between 35 and 55 grams or so. Sometimes a little more, sometimes a little less. If they are too small they will need supplementing from you.
2) Buy and keep on hand some KMR kitten milk replacer formula, some nutrical for ferrets (both of these can be found at Petsmart), and some Gerber baby rice cereal. Also some eye droppers for feeding, in case mom doesn't produce enough milk. Jo Ann has a video somewhere to show you how to feed the babies properly if they need it.
3) Measure your cage bars for the kits. If they have spacing of greater than 1/2" you will need to add wire mesh, as Bright Eyed said. You will need a roll of 1/2" x 1/2" hardware cloth, some c-rings or j-rings, and the pliers for applying them, which you can get at a farm supply store.
So a shopping list for today would include:
2nd cage for dad
1/2" x 1/2" wire mesh
c-rings or j-rings
pliers for applying rings
cranberry or apple juice (no sugar added)
digital kitchen scale (weighs in grams)
KMR kitten milk replacer
Gerber Baby rice cereal
Nutrical
Eye droppers
After you get all of that please let us know the weights and we will see if we can walk you through what comes next. I hope everything is ok. Keep us posted!