She is absolutely stunning!
Is she a mouser? If so, please be very careful about allowing her around Felix. He is in the rodent family.
Is she strictly an inside cat, or does she go outside sometimes? If she does go outside on occasions ... be very cautious ... if a cat in the neighborhood has, or is a carrier of, feline distemper (cat pneumonia), which is highly contagious, and she walks over the same area that cat has been, she can carry the feline distemper inside ... if Felix is exposed to it, he could pass away in 24 to 48 hours ... it is very deadly for chinchillas.
I don't want to be an alarmist, but it is better to know these things and avoid them, than it is to find them out after it is already to late. Simple precautions are so easy.
Jo Ann