Open up her mouth and look inside..do you see mucus or red irritated areas ?
When her mouth is closed do you sometimes see bubbles of saliva coming out the side of it?
Can you hear her breathing or clicking regularly?
Is she opening her mouth to breath?
Is her energy lower?
Has she denied food or regurgitated recently?
If the answer to at least two of these is yes, then you need to take her in for bloodwork to see if she has an RI. An RI is often a result of other problems and the vet could help you work through this.
How long have you had her? How do you feel she could have gotten an RI ? In order to get an infection , the immune system must be compromised by improper temps, stress, or bacteria being too heavy in the cage.