In a video shared to social media, the 44-year-old model explains how Evelyn, nine, decided to educate herself about her father’s condition and then act on it.
Admitting she felt emotional even speaking about it, she said: “So I have to tell you this story, and I’m going to try and do it without crying.
“Because when Evelyn told me this story, I was an absolute puddle.”
The mother-of-two went on to explain how after looking up “fun facts about dementia”, the youngster learned that people with the condition “can become severely dehydrated”.
She added: “Now, that’s not funny, but it’s kind of funny. She really is her father’s child because these two love some random facts.
“So I said to her, ‘Evelyn, we will always make sure daddy has a bottle of water in hand. Thank you for letting me know. But that is the most loving and compassionate thing that you can do is to be curious and educate yourself on your dad’s disease’.”
In addition to Evelyn, the couple are parents to 11-year-old Mabel. The Die Hard actor also shares daughters Rumer, 34, Scout, 31, and Tallulah, 29, with ex-wife Demi Moore.
Clearly only learning of her younger sibling’s efforts via the post, Scout wrote in the comments section: “Omg Evelyn!!!!!!! That story made me a puddle of tenderness.”