Mine was slow growing at first. If yours is eating the right amounts, i wouldn't worry too much for now. Mine only grew about an inch in the first month and then had a growth spurt- growing 5 inches in 2 months. Ive had her 3 months and she started at 9 inches and is now almost 15inches.
jharris08 is right about the hide- babies will spend most of their time in there and not enough time basking. You could always put it in on a night time, after lights out.