Welcome to the Android Community!
It sounds like your daughter may have changed the phone's primary account to her own. Depending on what phone you have, the process in checking this may differ.
Lets try this out: From the homescreen, press the menu button on the phone and go to Settings. Go down to the option Accounts & sync. Near the bottom, you should have a list of different accounts that are linked to the phone (Gmail, Facebook, Twitter, etc.). Look for the Gmail accounts and see if there is one that does not belong to you. Click on that account and on the next page at the bottom there should be a button that says "Remove account". Click that to do so.
If this does not fix the problem, let us know and we will further aid you.
Again, welcome and hope you enjoy your stay!
