that's good, that you are watching the temp. and she is doing well. But i feel it necessary to let you know about the danger your chin is in.
Using a fan to cool your chin isn't enough, fans work by blowing air onto sweat to evaporate it faster, when it evaporates, the heat goes with it, but sense chinchillas don't really sweat, this doesn't work, the only way to cool your chin is to physically lower the temperature of the environment, usually accomplished by adding an air conditioner, or moving your chin (cage and all) to a cooler aria in your house. If this only happens very rarely (like only 1 or 2 days a year, and only by a few degrees) you may be able to cheat a little and add ice, frozen rocks, or something similar to your chin's cage during that time. overheating is one of the leading causes of accidental chin death. please be careful. chins should not be kept in environments over 70 degrees F.
I am NOT saying you are a bad chin owner, because you obviously care about your chin a lot and look toward niblit's safety, those are qualities of a GOOD chin owner. I believe that, like many good owners, you were simply misinformed, and correct information will help. so please have fun with your niblit
and continue being such a good owner