My Daughter (age 12) Just Started Having Her Period. She

My daughter (age 12) just started having her period. She has had about five of them, and each time they have occurred with only 15 - 20 days between them (from day 1 to the next day 1), and each period lasts roughly 3-4 days. Should this really be happening so often for someone who is just starting to have a cycle?