SMS text messages go to Customers through whatever message app the Customer has on their phone. Right now, the only way for a Customer to contact an Instructor is to reply to a text message that was sent previously.
Workaround:
The Instructor can send a text message before class starts for the year and have the parent save it. So if the Enrollee is going to be late or absent, they can reach out that way instead of contacting the school.