Determining age

My girl just bought a baby ball python. She wants to determine how old the snake is but she's not sure how to do so. The pet store where she purchased it couldn't tell us when we bought it. So how does one determine the snake's age? Any help would be appreciated.

I cant think of any accurate way to determine age... Just going by size isnt very accurate because they all grow at different rates which are greatly affected by how often they are fed and what they are fed. If its from a pet store, its probably under 1 year old. A random guess would probably be ~6 months old. Do you have a way to weigh it and/or post a pic?

I think weight is a good way to measure age, and just the overall appearance... A dustiness I suppose. Of course, the oldest girl I have was WC and she does look older, maybe around 5 years, so my experience is limited.