hello
If the tortoise is smooth and healthy no worries
heat and diet are the control factors for growth in my opinion and if they are being covered then this is the size the tortoise should be
some grow really fast some are slower
focus more on a balanced diet and a cool habitat
size comes with age
doesn't matter in the end they all get huge
enjoy the youth
It doesn't last long and you will miss the times when moving the tortoise was easy.
best regards
jeff
planet reptiles