In hindsight, where the signs there that Kelly was sick?
I like most of you, didn't know that Kelly Preston had cancer. But look up John Travolta's Instagram, and watch their family "Happy Holiday" videos. Her appearance changes drastically between their "Happy New Year" video and the "Happy Easter" video. It even looks like she's wearing a wig at Easter. Outside of that, she hadn't been photographed publicly at an event since 2018? I even read a comment theorizing that John was finally "embracing" his baldness as a sign of solidarity for his wife during this ordeal.
https://i.dailymail.co.uk/1s/2020/07/13/10/30695704-8516549-Actress_and_former_model_Preston_and_Travolta_are_pictured_with_-a-37_1594633134964.jpg
https://i.dailymail.co.uk/1s/2020/07/13/10/30696928-8516549-John_Travolta_and_his_wife_Kelly_Preston_on_February_24_this_yea-a-46_1594633135437.jpg