Males have little points on the back of their back feet called tarsal spurs. It does not appear to have any from the pic you provided. At first I thought I saw a spur, but I think that is the other side of the foot that I am seeing instead. You could always post a few more pics to be certain. As far as age, pics can be very deceiving, so you really need something to compare body size to like a ruler, your finger, etc.