After this, Debbie and Mark have sex in on the kitchen floor, reminiscent to the scene in the first episode where Steve and Fiona also have sex in the kitchen, in the same place as Debbie does. Debbie does not return in 2010 for series 7. We find out from Frank's grandmother, who comes to visit, that Debbie has joined the army. At seventeen, Debbie perhaps had no wish to allow her role as the driving force of the Gallagher household hold her back from her potential. Liam, who had been virtually brought up by Debbie since the age of four, has taken on her former role in the Gallagher household or maybe after Child Services incident she realized she was unfit to being a parent figure to her dysfunctional family and joined the Army to find her place.