Making hat pattern larger?

The above pattern is for a knit hat for a baby/toddler from what the picture shows, the pattern doesn’t say.

How would I make the hat larger for a 10yr old? I want to make this for my neice who is penguin crazy (like her Aunty). Thought I’d just add 5 stitches on each end keeping the pattern in the middle the same size. What do you think??

Another thing, the pattern says the circumference of the hat is 18", that sounds pretty big for a toddlers head doesn’t it??

I know I should measure my neices head but it’s supposed to be a surprise.

Thanks for your help!

CJ

Toddlers have pretty big heads, so the 18" is about right. Adult heads are anywhere from 21-24", so childrenn would be somewhere in between. The pattern is knit with worsted yarn and size 6 needles, you could go up to size 9s and follow the instructions in the pattern.