DD had an estimated 50%+ hearing loss in one ear due to ear infections and problems at about 18 months old. The ENT told us to try some strong AB's and then go on a totally dairy free diet for 3 months, and to come back for a check up. He said if it didn't work she would need grommets. We did all of that, and she was totally gunk and infection free as of then. We were told to reintroduce the dairy foods as per what was normal for 3 months , and she got inflammation and eventually, another ear infection. So we went totally dairy free again for 2 years, and slowly reintroduced dairy and she was/is fine now (she's 6 now). She has never needed grommets and hasn't had an ear infection in years.

DS1 was starting to get ear infections at around 18 mths/2 years too, so we went totally dairy free for him too, though not on doctors orders. But he only has had one ear infection since. We give him dairy some times and he starts to say his ears hurt or are hot if he has too much, so we know we need to cut back then.

DS2 hasn't had ear issues, but he's been dairy intolerant since he was tiny, even to the point that I couldn't eat dairy while he was breastfeeding.

It must just run in our family. I was dairy intolerant when I was a baby and had to have specially made soy formula when mum stopped breastfeeding me.

I would say to try it. It can't hurt her, and is way preferable that her having to go back to have more grommets/suctioning.