She captioned the heartfelt post: “And the sun sets in the West… In Bunbury this week to say goodbye to my Father-in-Law. Leslie Lancaster was 78. Safe travels Les.”
The circumstances surrounding his death are yet to be confirmed.
Leslie is the father of Barr’s film editor husband, Andrew Thompson.
The pair have been happily married since 1995 and share two sons together, Lachlan, 16 and 12-year-old Hunter.
The Channel Seven journalist lost her own father to a heart attack in 2001 when she was pregnant with her first child.
This article originally appeared on New Idea.