I noticed yesterday when handling Noodles that she was making a very faint clicking noise when she's breathing. The only reason I even heard it was because she stretched up onto my glasses and rested on my ear afterwards. I took her and listened closer and it was very faint but definitely a clicking sound. I know this can be a sign of an RI, so I checked her mouth and didn't see any mucus, no bubbles, and there is no discoloration in or around her mouth/nose. She isn't rubbing her face in her enclosure and there aren't any mucus smudges on the glass. So what i'm wondering is if a slight, very faint clicking is normal, or is it's the beginning of an RI? I'll absolutely bring her to the vet if I have to, but wanted some advice first. Any help is appreciated!

She's in a 20G enclosure
Her substrate is a cypress/aspen blend
Clean water every day
I spot clean when needed and clean/disinfect everything once a month
She has three hides, one on the cold side, one in the middle, and one on the hot side
Her temps are 76-78, 80-82, and 89-91
Her humidity stays anywhere between 55% and 65%
I've had her for three months and she was never missed a meal, she's on rat pups
She sleeps all day and comes out for a while at night, usually basking on the branch I have in her enclosure, does a tour of her home, and goes back to sleep.