Up to around a year old they should receive pellets everyday as well as veggies and then after a year, pellets every other day. I've heard that 1 inch of growth a year is good as well, but that they will grow more than that the first year. So at around a year old, 3inches in length would be about the right size. (but like Jen said they all can grow at different rates) And considering that when they are hatched they are anywhere from close to an inch to an inch & a half, I'd say Tortuga is a fairly young hatchling.
When we got Koopa he was about 1 1/4 in and a new hatchling. He still had his egg-tooth (which disappears about 2 weeks after birth) so we were able to tell his age from the start.
