My late Jewel had a big growth spurt late in life.
From 2019-2021 she grew quite a bit.
I have no idea if this was an individual trait, or if it happens with carpets more so than other species.
I don't consider a 9-10 year old snake "old" so seeing growth wouldn't surprise me. Seeing that your animal is only 5 years, I would expect more growth.
I never weigh my animals but when I can get them on the deck rail and they stretch out I will try to measure them.
That is a good looking snake!