The 70-year-old singer joked the former One Direction hunk is the secret "love child" of herself and Fleetwood Mac bandmate Mick Fleetwood and she loves the direction he’s taken with his solo career, instead of taking the "easy" option of mimicking the material of his group.
Asked about Harry’s version of Fleetwood Mac’s ‘The Chain’, she said: "He’s Mick’s and my love child. When Harry came into our lives, I said, ‘Oh my God, this is the son I never had.’ So I adopted him.
"I love Harry, and I’m so happy Harry made a rock & roll record — he could have made a pop record and that would have been the easy way for him. But I guess he decided he wanted to be born in 1948, too — he made a record that was more like 1975."
And Harry isn’t the only young pop star that Stevie feels motherly towards as she admitted it makes her very "happy" to hear that young female singers idolise her and she shares a special connection with a lot of them.
Asked by Rolling Stone magazine how she feels about young pop stars idolising her, she said: "That makes me happy because I didn’t ever have children, but I feel like I have a lot of daughters.
"I love Vanessa Carlton. She’s like my younger, younger, younger sister — like if my dad had divorced my mother and married a really younger woman, then had Vanessa.
"I’m so much older than her, but yet there’s such a little silken thread between the two of us when it comes to music.