Pure wool should shrink on a higher temperature and higher spin cycle. Do not hang it to dry but lay it down on a drying rack for woolen items

I would pop it in the dryer for a very short time to shrink it a bit!

i thought that heat was supposed to shrink things.

You could try washing in quite warm water and dry it flat. Don’t use hot water or it will be toddler sized! drying flat is really important. To help reduce stretching, roll it in a dry towel first to remove excess water.