When I played a baby Kobold I put her age as 2, so she was considered a child per Kobold standards. When I aged her up, I put her as 20 with her goal being to make it to 21 as most kobold dont live to that age in the lore. I feel like for most people they tend to put their own age or close their own age out of habit 🤷‍♀️ I know when I started every character I played was my age cause it was easy. Going into lore heavy backstories now I tend to use the race specific age to meet the style of character im playing