I bet she is fine for your AOW course. If she developed an ear infection, most antibiotics will take care of it in the typical 10 day course. I’m no doctor, but I’ve had my fair share of ear and sinus infections, especially during my first two years of diving. Every time I took antibiotics I was feeling better around day 5 and finished the course in 10. Depth shouldn’t be an issue. If she can clear past 5 feet she should be good down to 100+. If she is in any discomfort at the end of the course, I would suggest you delay your AOW dives and see the doctor again. This happens all the time and any good instructor will have no problem rescheduling. As for how to get back into it, yes slowly is always best, especially for the first clear. As a rule of thumb I always clear on the surface once just before I descend. I always say if you can clear on land, you should be able to clear underwater. It sort of lubricates the eardrum so I can clear underwater more easily, and I do it seconds before I go down. And if it doesn’t work underwater I NEVER force it. I just went on a 3 dive trip where I couldn’t clear on the first dive, but no problem on the second or thirds. No cause I could think of. Another tool I personally use is the Doc’s Pro Plugs, which you can do a search on this site and it should pull up lots of information. I never dive without them. Good luck and congrats on taking your Advanced!