I don’t know much about kids at all. Those are definitely higher than normal numbers. The 204 before lunch is in the diabetic range. If it is type 1 it will keep getting worse. Keep a close eye on her sugars, poor girl.
There are some other things that cause blood sugar spikes over longer periods of time, infections for one. There are a few different forms of diabetes too.
Other key symptoms would be that she drinks and pees more often. May also appear more tired, sleeps longer.
I was diagnosed at at age 5, and have clear memory of how tired and thirsty I was, and aware that I was peeing more. Mom brought me to doctor, who recognized by my breath, that I likely had diabetes. Sent directly to hospital. That was over 50 years ago !
Sounds like you are doing the right things.