Yes, it’s fairly common in DID systems

Thank you I have two kid alters named Bella and Lilly and I have max Roxanne sierra parker who are older than me I am 18

Oh yeah, most of our alters are younger or older than the body (21). It's a common thing I've seen in other systems I've talked to as well!

the only alter i have seems to be a bit younger than me, around 12-15.

We don’t really have anyone who’s strictly the bodies age… never thought abt that before huh!

There's only one orher alter that shares the body's age orher than me, and that's our gatekeeper. About 50% of our system is under the age of eight. Have a few teens and three older than me (23). One is 40, one is 30, and the other is ageless. Very very common for ages to be different. One part aged up seven years almost automatically. And he age slides between 14 and 19 depending on what he's trying to do. Age is often varied!