Is she still going outside? If so she'll have rolled in the dirt and gotten some in her ears.
I wouldn't suggest peroxide, just because it damages skin a little. And you have to have a steady practiced hand and know your cat (how she'll react) before venturing in with a q-tip.
What you can do, though, is go to a petstore or petco (or petsmart) and get some ear wipes. They're lightly dampened and you would just wrap it around your finger and wipe away what you could. Much safer and easier.
(I've also used damped, but very well wrung out wash clothes and paper towels in a pinch)
Once you can get to the vet you can ask them about it and get some drops to clean her ears - provided that you're not seeing a lot of wax and it has no smell, otherwise it's more important and can't wait.
And yeah, some cats have a bit of visible ear wax, more so if they can get out and roll in dirt. I have one that does and food changes drastically decreased it to a just a small amount. It's still there, though. It's been cultured four times and is always negative. I just wipe it out or let Tomas take care of it (Tomas likes to clean everyones ears...).
