"iTunes synced with another library on a different PC message" that the iPhone has never been plugged into.

My Daughter picked up an iPhone 5S from Sprint the other day. She connected it to her laptop and upon first sync but get a message that it is synced with another library on a different PC. . This is where it gets weird. The message references a PC name that I use at work and that she has never been around. Her iPhone has never been plugged into any other PC. I thought that maybe there was some kind of a link between our apple ids but there isn't that I can tell. I'm completely confused.