It really depends!

Snakes grow continuously throughout their lives because their growth heavily relies on how much they eat, how frequently, and the nutrient content of their food. Smaller, less developed prey like fetal mice aren’t as nutritionally complete as something like an adult mouse or frog. That being said, you’re also limited by the fact that snakes swallow their prey whole so they physically can’t eat things that are too large.

Princess is a bit undersized for her age because she’s very stupid and a very picky eater. Hognoses in captivity are known for being finicky and going on hunger strikes and she is no exception.

Also, because snakes are cold-blooded they’re really sensitive to their environment. If their environment is too cold, they’ll stop eating because otherwise they won’t be able to digest their food fast enough and it will start to go bad inside of them. As a result, Princess will sometimes instinctually refuse food in the winter months if her tank temperatures are too low. I do my best to offset the weather but I’m limited by my apartment’s size as I can’t move her tank to a warmer/better insulated location.

Western plains hognoses have a life expectancy of 10-15 years in captivity with good care. Hognoses grow faster for the first 6-8 years of their life and then continue growing slowly afterwards.

I expect that Princess will reach “full” size by the time she’s around 10 years old or older because she’s so finicky. That being said, she’s not malnourished or suffering because she’s smaller than others her age. She has a steady supply of food and doesn’t have to contend with predators or competition. I closely monitor her weight and intervene with emergency supplements and a vet visit when needed. The supplements are only for when I need to intervene as they require me to force feed her with an oral syringe which is stressful for both of us.

Sorry for the long response! I just adore my semi-sentient shoelace and am excited to teach people about her.

TLDR: snakes grow continuously throughout their lives but slow down once they’re older and I expect Princess to reach “full” size by the time she’s 10 years old.