When asked during an interview with Britain's The Times newspaper if it had been difficult meeting her for the first time, Jessie revealed: "God no! She's just six and absolutely lovely."
Jessie began dating the Hollywood hunk in October (18), although the couple didn't take their romance public until March this year, when they were pictured walking hand-in-hand in London.
However, she confessed that their relationship was scrutinised even before it had properly begun.
"Chan and I got photographed before our relationship was even a thing and that created such pressure. We've needed time to get to know each other. We've just had our first holiday together, which was wonderful, but that's all I'm saying," she told the Times.
Jessie also joked that she was attracted to Channing's cleanliness when they first began dating.
"Oh, I'm very happy on '21 Jump Street'!" she said, referring to the actor's 2012 movie. "I always look for a guy with a good sense of humour and good morals. And hygiene. A man who showers is very important!"
Jessie confessed to fans back in November during a concert that four years ago, she was told by a doctor she'd never be able to have children.
Despite the setback, Jessie told the Times that she's remained determined to become a mother.
"I might go down the route of adoption or even surrogacy," she said. "I pray that I have children the natural way, but if not, I'll deal with it."