John's birthday tribute to Jett came just less than a year after Kelly's death following a cancer battle. She was 57. Last year, prior to Kelly's death, both she and John posted birthday tributes to Jett.
At the time, John shared a similar shot of himself with Jett as he did this year, while Kelly posted a pic of her and her son sharing a hug.
"Happy Birthday Jetty! We love you!" John wrote, with Kelly adding, "Happy Birthday to our sweetest Jetty, we love you!!"