Mom (Catherine O'Hara)’s Timeline and Summary

Kate hustles to get packed, while Kevin whines at her. After he attacks Buzz, she banishes him to the attic.
After she and Kevin's dad accidentally sleep in, they race to get the rest of the family to the airport on time—leaving Kevin behind due to a wrong headcount.
When she realizes her mistake on the plane, she freaks out.
As soon as they land, she tries to contact home—but the phone lines are down, and the police insist that no one's at home, since Kevin won't answer the door when they send someone over.
Kevin's mom decides not to wait for the next available flight. She trades jewelry and other items for an elderly couple's tickets, and heads back by herself.
After arriving in Scranton, PA, she has a brief meltdown after the desk agent tells her there are no tickets left to Chicago.
Fortunately, a friendly polka bandleader, Gus Polinski, offers her a ride and she accepts.
The polka band safely takes her back to Chicago, where she reunites with Kevin, happily…and then the rest of the family shows up, having taken the flight she didn't want to wait for.