I was at the range yesterday, shooting next bench down from a gent with his daughter, age 6. Yep, pink cricket. Young lady was doing fine.
Most days, one of my granddaughters (the Anarchist-in-training) is shooting with me. She has been my shooting buddy for 6 years now, and is the young lady with the target rifle on the 100 yd line.
No one set age- when they are old enough to pay attention, follow instructions precisely, and understand what they are doing. People of ANY age vilating range rules or safety procedures are another matter.
Fellow took exception to the A-I-C shooting one day. She politely advised him that SHE was a member of the range association, and SHE was not the one handling a firearm while the range was cold.
(He was the one)