I want to put this wig on my daughter. How do I know what size to get?

Hmmm.... your doll will look kind of funny bald, no?

You would need to measure your child's head to know what size you need. The largest wigs we have are 15-16 with a few 16-17. Her head could well be larger than that. These wigs are made for dolls who won't complain about itching or seams poking into their heads. But for your daughter they might be very uncomfortable. I wouldn't recommend any of these wigs for a human child.