The 63 grams of sweets plus the 60 grams of carbs in the meal is a huge amount for an adult let alone a tiny nearly 3 year old toddler.
You should be reassured that your daughter's body had dealt with the massive overdose of carbs so efficiently to get back to safe levels.
You know yourself as an adult with diabetes how much insulin you would need to cover 120 carbs. But her body dealt with it naturally. So now you also know that you need not keep testing her blood sugar levels because she handles all the carbs that are thrown at her extremely well.
You said that you are going to register for some testing when she is three years old. Why? Why on earth why? Just because you have this stubborn belief that the next time you test her she will be slightly over what you think she should be therefore she must be heading for diabetes. Please stop worrying. And please stop testing her. It isn't necessary.