Headband size help!

Hello All, I have started knitting recently, finished scarf, hat for my husband… I now want to make lace headband as gift for my friends daughter. Today I made a lace headband for myself which I seamed and the length was 16inches. It fits perfectly for me, I am wondering if I try the same pattern, what should be the length for a little girl who is around 6 years old.

I would appreciate any help.

A headband size is probably similar to a hat size. Here’s a basic head measurement guide. You could ask the mom, too.