Sorry for the slow reply, but, that in itself doesn't connect it to an SMS number. That's just so she can contact a class as a whole, rather than individually.
The SMS connection lies in that every mobile number has an email address associated with it. So you can send an email to that address and it will be delivered to the device as a text message.
The SMS connection lies in that every mobile number has an email address associated with it. So you can send an email to that address and it will be delivered to the device as a text message.