Carissa Van (aka Debbie's mom or Mrs. Van) is the mother of Debbie voiced by Jenny Yang. She is introduced in Beef Mommas House Adventure. She has long black hair.
Prior to Moon visiting her, he asks his dad Beef if he can go to "the Van's house", mirroring an earlier reference where Gibbons called her Debbie Van, indicating her mother is likely Carissa Van.
This was confirmed in season 2 when it was revealed Carissa is Debbie's mother and she and Debbie's father, Ken, are divorced.
In Season 4, Carissa and Beef are officially dating.
Bethany mentions in season 5 episode Ghouls Rush in Adventure at Scone Moose that Carissa makes her check ID for people purchasing a Joltin' Jazzed Max Caff Dulce De Leche Latte before being bribed by Moon to look the other way.