They may have long since split, but the 'Uptown Girl' reached out to everyone's favorite 'Piano Man' to let him known he was in her thoughts.

Christie Brinkley is showing support for her ex-husband Billy Joel following news of his recent brain diagnosis. The supermodel, who shares daughter Alexa Ray with the legendary singer, posted a video on Instagram Saturday -- just one day after Joel revealed he had been diagnosed with normal pressure hydrocephalus.

Billy Joel is "not ready to retire" amid his normal pressure hydrocephalus diagnosis, sources tell PEOPLE. The singer announced on Friday, May 23, that he would be canceling his upcoming concerts after previously postponing shows through June.