Wasting time
Helping out new colleagues is a kind as well as a sensible thing to do. You make someone feel welcome, and you help them get to grips with their job quickly so that everything runs more smoothly. It’s just common sense.
If you end up in a situation where they start to behave unkindly themselves, though, then you’d be just as annoyed as the narrator. He wants to help her fit in with the team and work well, but she’s not cutting everyone else the same amount of slack. She doesn’t seem like a team player to me.