fridge filler
A fridge filler is a member of the family (usually a mother) who's other members(usually busy husband and arsey kids) who see the fridge fillers only role to fill said fridge for them daily and see no sense of individuality or importance in them otherwise.
Debbie is just a fridge filler for that family. God bless her she has her own identity but that lot just want her to fill the fridge from Sainsburys!!