Theory on young girls who get their period prior to marriage age

!This is so random but I thought maybe the few pinks we see at Agnes' school are perhaps girls who got their period "too early" as in before becoming plums, as I'm pretty sure in the books the school is specifically a marriage preparatory? Potentially a girl who gets her period whilst still pink will be sent to the preparatory in order to be prepared for marriage the moment she is a eligible as she will become a green the moment she becomes a plum (age 12??). This would maybe explain why there's specifically a small amount of pinks already at the preparatory and how Gilead gets around not marrying off pinks they deem too young to be ready for marriage despite menstruating? Just a theory tho lol I'd be keen to hear others ideas on this!<