In the bible, I don’t think the devil has any kith or kin. However, in the folk tales of many lands the Devil’s wife and the Devil’s grandmother are occasionally referred to. They usually help the Hero get something he needs form the underworld.
Lilith, Adam’s first wife, is said (in some legends) to have left Adam and the garden and gone her own way. Some legends say she had children by demons. There have been several threads about Lilith and her origin, relationships and mythology. Please use the search button located in the upper right corner of your SDMB window.