Kristin Minter as Heather McCallister
As the eldest sibling of the McCallister family, Healthier McCallister bears a lot of responsibility when it comes to her younger siblings being organized. We see this when the family is scrambling to get ready for the airport in the morning, Heather is responsible for seeing all the kids into the van.
However, the mistake comes in when she accidentally counts a neighbour’s boy, thinking that it was Kevin. This is the moment of miscalculation that finalizes Kevin being left behind in the home.