YW.
Age can't be determined by look. I adopted my sister's 2 year old BP in November and it was only 600+ grams and I have a one year old male lesser that is probably around 600-700 grams now. From my observations of conversations and BPs, the average seems to be 1000grams in the first year. Each snake grows at their own rate though so it's only a guide line and not a rule.