Measuring for a goalie stick is a very difficult task. The most important feature to look for is paddle length, not overall stick size. The correct paddle length helps the goalie maintain a correct stance. The goalies height should not be the deciding factor in selecting your paddle size. The decision should be based on the goalies stance. This is very hard to replicate precisely when you're not on the ice. The aim is to have the stick flat on the ice in the middle of your 5 hole when in your stance, with your blocker right next to your pad but with no overlap.
Another consideration should be measurements brand to brand are not identical. For example, a 26" in Bauer may not be identical to a 26" in CCM, True or Warrior
We would suggest, if you have any doubt, speaking to one of our staff members, your coach or experienced goalie to get advice on appropriate sizing.