Not sure if you know this, but your wonderful book has it's own Wikipedia page. As I was browsing through it, it said Alina Starkov is a 15 year old teenager. Now I'm not one to believe in a Wikipedia page, but I don't find her being a 15 year old plausibl

Oh lawd. I haven’t looked at the wikipedia page. Dare I?

Alina and Mal are 17 at the start of the action in Shadow and Bone. Their exact ages are unknown since they’re both orphans and refugees. (At Keramzin, every child without a known birthday is given the Duke’s birthday.) And yes, Sturmhond is in his early 20s.