How to determine age of a juvenile leo?

[yeahcastro]

Hi there! I purchased my leo from petsmart and of course they were unable to tell me the age or gender. I understand that in time I will be able to determine the gender but is there any way of estimating how old he/she is?

I want to weigh and measure her but she's only been home a few days and think it best not to disturb her too much until she's situated.

I refer to her as a she as I am hoping she is female haha.

Thanks.