Since your daughter is four, it's my opinion that you should go ahead with the surgery. Usuallly, by age 3, the eustacian tube in the ear should be fully developed, and any inflammation of adenoids/tonsils, if developmental, should have corrected itself. If you are still experiencing chronic ear infections at that age, it's unlikely that she will grow out of it.
My 6-year-old had tubes put in, tonsils removed, and her adenoids out at age 3. The results were wonderful and immediate. I didn't regret it for a second. The recovery was easy, she hardly felt any discomfort after the initial discomfort of waking up in a strange place in some pain, and we were only there for two hours and went home.
Since then, she has actually had additional ear/adenoid problems. Her adenoids grew back and we had to have them removed again, and one of her tubes fell out which was immediately followed by additional infections so we had to have another one put in.
Some parents are hesitant to utilize medical intervention, and when frivelous, I understand why. However, I definitely think that ENT issues are important to deal with quickly, especially when it will exponentially increase a child's quality of life. The surgery is simple, quick, and your child will THANK you for it, I promise.
Your daughter will talk better, clearer, will hear better, rest more soundly, and you will notice a big difference.
Hope this helps!