Wow, many of those things will be making it worse.
When I was a baby I had a massive ear infection and have had problems ever since especially when I swim a lot.
But I have fixed it about 95% now. How ?
First thing is get a neti pot and fine Sea Salt and use it twice a day. It's very very good. Forget about the idiotic Western versions - the medics are too ashamed to say that the Indian yogis had the answer, so they have invented retarded syringes or whatever. Forget that, just get the original neti pot, twice a day.
Note : make sure you use fine Sea Salt (or fine rock salt) and that it is all dissolved. If you learn how to do it right, you should be able to use it 10 times a day without any discomfort.
Second thing is teeth. How are her teeth ? Because the teeth are the epicentre of infections in the head. I use : Panasonic EW1211W, it's extremely good. Cleans house. Never fillings. If I have some dodgy smell coming from a tooth I add in some Hydrogen Peroxide into the EW1211W and clean the teeth. Also I use Bentonite / baking powder tooth powder now.
Third thing is after I shower in the morning when the earwax is soft I use some loo roll to quick wipe the ears and pull out some wax.
I recommend not putting anything at all in your ears but I am not expert about that.