Hi Donna and welcome to the Disney Parks Moms Panel.
Unfortunately, you must be between 4 and 12 years of age to participate in
Jedi Training: Trials of the Temple.
Based on the circumstances, you could always stop and speak to a Cast Member during registration for the show at Disney's Hollywood Studios to see if it would be possible for your daughter to participate but strictly speaking, at 15 years old, she is over the age limit.
The good news is however that there are lots of other great
Star Wars attractions/experiences at Disney's Hollywood Studios for you and your daughter to enjoy including meet and greets with both Kylo Ren and
Chewbacca at the Star Wars Launch Bay.
Wishing you a magical trip filled with memories which will last a lifetime!
Emma