Yes, she is small for her age. That has to do with her feeding on mice and not eating consistently.She wouldn't necessarily eat every week and I couldn't get her to eat two in a row. BPs are interesting in that their size is is not based on their age, unless they are a typical feeder. But if they don't take in a lot of calories, their body doesn't grow. That said, my girl looks plenty fat. She isn't at all malnourished looking. She is just small for her age. If you read Dianne's post above, her 2015 boy just reached 509 grams. He's almost four years old.
I have another female that is four years old and under 1200 grams. I stopped tracking because it was driving me nuts, but I know at one point she had eaten only 17 times in 73 weeks. I have tried everything from live to frozen thawed, Mice , Rats, and ASFs. She is just a finicky eater and until I breed her probably always will be.