Chinchillas are very clean, so you will notice her cleaning herself more often ... several times a day.
She will be slightly swollen, with a slight discharge and usually a tiny dot of bright red blood can be seen below the discharge.
The male will be very excitable and usually doing a mating ritual known as the "Swish, Swish Tail Dance". He will be swishing his tail back and forth, then do a little hop-hop, swishing the tail and repeating the little hop-hop. If you can see his face, often they will even look like they are smiling! He will do this off and on until the female says yes.
Of course, she will not say yes until she is in full season, in the meantime, she may become annoyed by the constant asking and spray him a few times.
He may become over eager and try before she says yes, then they will usually end up in a little scuffle ... no blood, but usually a little fur flies. If you see biting or blood ... separate them.
I'll post pictures of a female in season.
Hope this helps!
Jo Ann