Upvote:6
Westjet allows children to travel without an adult from age 12. They have an optional Unaccompanied minor service for 12-18 year olds.
Westjet's ID requirements for domestic travel state only "Identification required"
must be presented during boarding at the gate and the name on the ID must match the name on the boarding pass
The list of acceptable identification types, besides a passport, is presented on the linked page.
You may wish to call Westjet and ask whether they can annotate the passenger record with the More Assistance/Meet and Assist (MAAS) flag. I'm not certain this is suitable/available for this circumstance, but is typically used for mainly self reliant passengers who may need some extra help, i.e. elderly or young passengers.
It would also be recommended to ensure your child has some printed contact information for parents/guardians at both departure and arrival airports.
Interestingly, for others considering travel for children who don't wish to travel alone, Westjet also offers Guardian Fares
The guardian fare allows parents or guardians to escort their children, at a reduced fare, to their destination and then return immediately to their departure city