First time

My daughter is 10, and had her first mensuration last month. I downloaded eve on her phone to track her periods, only I have access to it as I set a password.

Now for my question: Should I prepare for her periods to be irregular at first, or can I ASSUME they will be on time? It has been 35 years since I had my first. And I’ll be honest, I ONLY remember waking up to it that first day with blood in my bed. I was 11.

Update: she has not started yet, so I can safely assume she will be irregular for awhile. Thank you all for the advice and input.