The Data symbol in the notifications bar will only show if there is data being streamed to or from the phone. It is not a persistent notifier.
Did you test that?
Is she able to actually stream data at all?
Does she have a data plan?
If she has a data plan and is requesting [or trying to send] data and it's not working, check to make sure it is enabled. Settings> Wireless & Network Settings> Mobile Networks - Data Enabled is ticked.