Hello Meixin,
I am happy that you are on this journey with your daughter! There is nothing much that you need to do. Most of the responsibility will be on your daughter to clean her teeth and braces well. Her dentist probably would have taught her how to clean her teeth with braces on.
Other than cleaning, she also needs to avoid chewing on hard food e.g. nuts, crab, ice cubes, to prevent the braces from coming off the teeth. Apples also need to be cut into bite-sized pieces instead of eating off a whole apple.
When she sees her dentist for her monthly braces adjustments, the dentist will be better able to advise if she’s taking care of her braces well.