That's a pretty personal सवाल to be asking, even here. I don't know whether it's invasive या if it takes balls...or if you're just some creepo on the internet who wants to know when little girls started bleeding out of their lady parts.
आप shouldn't really ask that here. I feel that it's personal to many out there. So I'm going to teach आप about the menstrual cycle.
Girls and women usually get their first period between the ages of 9 to 15. I've noticed most people get it around the age of 13, though. A woman has periods until she reaches menopause. Menopause occurs between the ages of 45 and 55. Hopefully, आप already know this. .
Here's a link to learn more. https://www.womenshealth.gov/a-z-topics/menstruation-and-menstrual-cycle