Yep, seems about right to me. Ana Gwyn is roughly a year old and Tonks is about 6 months, and they both shed almost exactly once a month. When you consider the ten or so days of symptoms that lead up to shedding, that means I'm seeing signs of the next shed about 2-3 weeks after the last shed. Growing babies need to shed a lot to make room for new growth!
EDIT: Of course I say it's once a month, but when I just went back to check my records, they last shed on 9-8 and 9-17, respectively, and I only yesterday (10-24) noticed their bellies getting pink. So I say once a month, but it's not perfectly once a month. For a very young snake though, every 4-ish weeks is just about right considering their rapid growth at that age. Even my baby bullsnake seems to be on about a once-a-month schedule, though I've only had him long enough for one shed around 9-28 and his belly is turning pink today.
(Except that one time when Ana Gwyn got a very small injury, and it seemed to trigger a shed to get rid of the damaged scales... that time she shed on August 23rd then again on September 8th, only 16 days later)