I sugest getting them fixed asap
My 5 year old just had surgery today (1 and a half hours long) for her teeth under general at the hospital. She had one extraction, 2 pulpotomies, 2 restorations and like 10 cavities filled. We knew she had some issues but had a super bad dentist that told us our insurance would not cover the general anesthsia at all. After seeing him and getting a second opinion a year later we had the surgery scheduled a week later. I am so glad it is done.
My girls have weak enamel. My son is 9 and has never had a single cavity. My girls always have 1 or 2. My 7 year old has had 2 surgeries (she ruined her teeth with cyclic vomiting syndrome) and now my 5 year old.
My 3 year old has 2 cavities getting fixed next week.
I am a firm believer that you cannot heal cavities, they only get worse and then get absessed and need removal. Its not something to take lightly.
The quicker you get it done, change habits and food habits, the less decay there will be. Some people are predisposed to awful dental issues but flossing, cutting out sugar and brushing 3 times a day can really help. And sealants are a must for kids prone to cavities.