did you turn on/off your data on certain apps? check your cellular settings and scroll all the way down to whichever app you need to surf the web (i will assume your using safari), and make sure the switch is toggled on. Let me know if this works, or...
if you turn off both your data and your wifi, you should be able to send SMS messages (the green messages) instead of using imessage (the dark blue messages) make sure you have allowed her to actually send sms messages on her phone. go to settings > ...
