Simpson donned the look for a holiday production at her older kids' school.
"These beautiful kiddos did an amazing job performing on stage in front of a couple thousand people for their school holiday concert ? #MAXIDREW #ACEKNUTE," she captioned a family photo of herself and husband Eric Johnson with their older kids, Maxwell, 7, and Ace, 6.
Johnson even gets in on the holiday fun, wearing a Christmas sweater with a shirtless Santa complete with lots of abs and muscles.
"Getting a family pic on Thanksgiving was a task, but we did it before the pajama change for the car ride home!!" Simpson captioned the family photo. "I woke up this morning with the continued warm and cozy feeling of gratitude. Hope everyone had a blessed Thanksgiving! ?"