In this country, I think it's true to say that regardless of how you have your phone, if you have a number, you can receive text messages free of charge. Is it different there?

(Yes, it would be nice to have reminders also go to email, and it would be worth looking at this specific service to see if there's an option for that to happen automatically that can be turned on. But the teacher is doing something she isn't obliged to do, in the interests of the children; you obviously can't demand it.)

Email: my username, followed by 2, at google's mail