I absolutely agree with all the comments so far. Here's my add-on: What is your feeding schedule and prey size? She looks small for 2.5 years old. Length doesn't matter nearly as much as weight. There is no set in stone size they should be, but my guess is that she is either a male, or underfed. Get a digital kitchen scale ($25 at Walmart) and weigh her monthly or so (keep a record). This will help you know when to worry if she goes off feed, and when she is getting up to breeding size (general rule of thumb is 1200-1500g, since she will be old enough next winter, just needs to put on weight).