Does she have a blackberry data plan?
If she does she needs to go to her TMO account and register it to the network. Should be on the main page on the bottom left under Messaging. The link should be Blackberry Email set-up.
It will probably ask to input the IMEI and PIN so it registers to the network. Also you can send out the service books needed to send MMS. That should also be located there.
Let us know if you have any more questions.