Taking her to the vet isn't really going to do much good right now, most chins don't show any signs of being pregnant until they are about to or give birth. The only way to tell if a chin is pregnant is to do x-rays, which is dangerous since they will likely have to put the chin under anesthesia to do that. Also the stress of going to the vet and handled can hurt the kits or cause her to abort them. Chins are pregnant for roughly 111 days +/-, so it's pretty much just waiting and making sure she is comfortable and getting good food for now. Right now you should read through some threads on the forum here about
breeding, if you can stomach it I would highly recommend reading through some of
the horror stories of things that can go wrong so you know what to watch for. Also let your parents know that she may need emergency vet visit if things go bad. Breeding chins is not for the faint of heart, a lot can go wrong. I don't know how old you are so I don't know if you have a job or credit cards, but an emergency c-section on a chin for example can easily be $2,000 or more, just to give you an idea of worse case money wise. You can call around to vets offices too if you haven't already to see what ones even take chins in your area should the need arise. Also make sure you find one that is also open or at least takes emergencies at night, they tend to give birth at night.
I've only had one set of kits years ago, and done research, so hopefully someone with more experience will chime in. Some other advice I can think of is, it's best to also no handle her much, if she is pregnant you can hurt the kits. Baby proof the cage, meaning no bar spacing wider then 1/2", no ledges, wheels, and once the kits are born you may need to remove the hiding house so she can't get away/hide from the kits. Make sure she is eating her food, and you can also add alfalfa to they hay you give to help increase protein and calcium.