Hollywood's favorite caregiver, Connie Simpson, 57, opens up to Life & Style about her A-list clientele.

The baby whisperer (also known as Nanny Connie) shares that she was set to move into Jessica Biel and Justin Tinberlake’s house two weeks after the birth of son Silas, now 3.

But two days after the delivery, "[Jessica's] assistant called and asked if I could be on the next plane out," Connie tells Life & Style. "The baby wasn't sleeping. I was like, 'OK, I’m on my way.'"

"Jessica was eating cabbage," she says. "Cabbage is the worst thing in the world you can have [when nursing]. The baby was crying because he had gas!" One small diet change made all the difference: "Everyone started to get sleep," she says, "and was on track."

jessica biel and justin timberlake

Nanny Connie says that another one of her clients, George Clooney, was prepared when he and wife Amal, 40, welcomed twins Alexander and Ella in June 2017. "He knew how to change a diaper," Connie tells Life & Style. "He did it really well, and I gave him kudos for it."

But George, 57, wasn’t satisfied. "He would watch me [change diapers] and go, 'Wow you did that on your lap!' I’m like, 'Yeah, George, I’ve been doing it for 30 years!'" The actor's parenting philosophy? Practice makes perfect. "He stepped up to the plate whenever it was time," Connie says. "He pretty much embraced the situation and did a really good job!"