If it really is kits kicking you see, and not digestion and gas, then she could be ready to pop anytime now within the next week +/- a few days. Are her nipples visible yet? They normally get a bit longer and reddish when she is about to give birth and she may pull fur out around them. Unfortunately some chins show little to no signs until you wake up to a kit one morning. I would get her into a kit safe cage now, if nothing else it will give her time to settle in to a new cage before the kits are born and help lessen the stress. I would also make sure you have a vet you can call at any hour that knows chins. Complications are not unusual and they tend to give birth in the night or early morning. It's better to have a vet you can call and not need it then to need one and not know who to call. Also keep in mind that if a c-section is needed it can end up being a couple thousand dollars.
It's best not to give treats since you want only good nutritional things going into the female. You can give the female alfalfa hay, the extra calcium is a good idea. Try not to handle her unless you have to, you can easily accidentally hurt the unborn kits. Also make sure the cage doesn't have any high shelves that she could fall from, and you may need to remove the hiding house once the kits are born so she can't escape them, lol.
You also want to get a scale that measures in grams if you don't already have one, the best way to make sure the kits are growing is to weigh them daily. It takes the female time for the milk to come in, but should within a day. If it doesn't you will need to hand feed the kits, every couple hours 24/7 until they are weaned.
I would also check out some of the breeding thread on here if you haven't already. It's best to be prepared for anything that might happen.