She's always had a tiny bump on her jaw for as long as we can remember, but all of a sudden it got HUGE! We used a needle to drain it tonight and it was all pus. Looks infected to me, based on what came out of there. We cleaned it out as best we could but it looks like it will need drained again. We used hydrogen peroxide on it and then I put some ointment that I have for birds and reptiles for cuts and whatnot - it's aloe-based with a numbing agent. What would be the best course of action from here? We've moved her onto plain white paper and cleaned everything. Do we just keep draining and sanitizing until the infection clears up? That's how I've always handled this sort of thing - on humans or animals - but it's so near her mouth I don't want her to lose her appetite and I certainly don't want to do the wrong thing. What could have caused this?

Here's a photo: