Gwen Altamont is a fence for thieves.
A long time ago, before Selina Kyle became Catwoman, Gwen and Selina were partners in crime and small time thieves.
Gwen Altamont reenters Selina Kyle's life at the funeral for their fellow friend, Lola MacIntire. The pair meet up with each other afterwards so they can catch up. Gwen tells Selina that she is a fence now and would be willing to fence for her.