She doesn’t have any.
Have we seen any newWho companion’s friends, actually? I mean, we see they have social groups–Rose and Mickey in World War III, Martha in The Lazarus Experiment, Donna in The Runaway Bride, and Amy and Rory in The Big Bang and The Power of Three, but I think Amy’s the only one where we’ve met specific, individual friends, and even there it’s only one and only for about a minute.
Clara’s a friend of the Maitland family; she appears friendly with Adrian, though Danny is in a different category. We meet Julia in Smith and Jones, but she’s only established as Martha’s friend in her Myspace account. Donna made Nerys her bridesmaid and appears to genuinely loathe her.
Rose had Shareen, who was mentioned a lot but we never saw her…