"Happy birthday darling Sam," the 75-year-old wrote. "Where have the years gone? You are so special to everyone, poppy and I love you so much. 13 years today."
Fans were quick to comment their birthday wishes for the now-teenager, with some even pointing out the youngin's resemblance to his grandfather.
"Happy birthday Sam," one fan wrote, "I can see a little Bert there."
It was a hard end to the year for the Newton family as Bert, 82, was rushed to hospital.
Posting a picture of the Aussie icon in his hospital bed, Patti shared the news with her followers back in November.
"Bert's been in hospital," the performer wrote. "All good. He's got a lot of living to do".
By Christmas, the 82-year-old was pictured out of his mask and surgeon's hat and back celebrating with his family once more.
"Beautiful day celebrating Christmas with wonderful friends and family," Patti wrote on her Instagram along with Bert and his six grandkids.
It's clear the king and queen of Aussie television cherish all the time they have with their family.