I would think at her age that she could handle a 20-23% feed. Purina recommends 20% after 8 weeks old or 23% gamebird for meat turkeys. My feed stores here carry gamebird starter (23-24%) and flockraiser 20%. Avian vitamins are pretty much the same for all species, but make sure it has thiamine...
Thanks for the pictures. She looks content and sweet. If you have a balanced chicken or gambird feed, you can mix a bowl of that to an oatmeal consistancy with a lot of water. Poultry Booster, a vitamin/mineral supplement can be added to food daily.
I also will use 1/4 to a 1/2 of vitamin B complex crushed over some food I know they will eat, such as some egg. Even better is to sprinkle a little nutritional yeast on food, and it has B vitamins for leg health. My chickens like the taste.
When splinting a bone, if the fracture is not reduced with good placement of bones, the fractured bone can heal crooked. Most of us cannot afford vets and xrays for poultry, but that is the best way to deal with a fracture. There can be nerve damage and complications with open fractures as well...
You might want to try her in a chicken sling where she is suspended and she will be off the leg until it heals. Broken bones can take several weeks to form a hard callus or thickening in the juncture of the bones. I know very little about turkeys or splinting broken bones, but here is a good...