After asking a bunch of questions about her health, they suggested that we should go to the hospital (I think this is the default answer if there isn't a clear-cut 'oh that's normal') so we did. One weird thing is that they suggested that her temp of 36.5 at the armpit was a bit low (!!)- I think she misunderstood how I took the reading.
As soon as we entered the ER at CHEO they triaged her; weight, O2 saturation, HR, BP and temp were all textbook perfect. I immediately felt better, but they wanted a doc to verify and double check her. End result is they have no idea why she has slight duskiness around her mouth, but they could find nothing wrong. RSV was ruled out as there was no where near enough mucous, she isn't having seizures, and she's not dehydrated. Her chest sounded fine, and there were no signs of heart disease. Oh, and the wheezy breathing is just normal nose-breathing baby sounds, but of course, once you're worried, everything seems wrong.
We have her one month check-up on Tuesday and will talk to the family doctor about it. I never, ever want to think that my baby isn't getting sufficient oxygen again!