Well... my best friends call me a bitch so... xD
My best friend calls me dude and my other best friend calls me my love or hun but I know its just something they call me because they care and it doesn't bother me at all. But yeah if its something that you're not ok with then they should respect your wishes. Just let them know that's its bothering you and ask them to stop. It won't happen in a day so I would be patient.
In what way is she saying it, is it an affectionate way, or a rude way, if it's rude, you need to put the foot down, if it's affectionate, then it should be fine, but if it's annoying you that much, like with the rude, put the foot down