Need advice about work. Can you help?

I'm a bank teller and I have been working at my job for a year now. I work with 4 other tellers. Out of those four 3 of them are my really close friends. The other teller that I didn't metion told one of her freinds that came to the bank how muck she got paid. Well, she has only been working here for three months and she gets paid more than we do. Infact we started out making way lower that what she started out at. She has had no banking expierence had there is no reason why she should get paid that much. Should I tell my boss that I was standing right next to her a heard how much she gets paid? She said it plain and clear and I was less then a couple of feet away from her when she said it.