Miley Cyrus (left) and Brooke Shields with her daughter, Rowan
Todd Williamson/WireImage; BAUER-GRIFFIN
Like most little girls, Brooke Shields's 4-year-old daughter, Rowan Henchy, "is obsessed with Hannah Montana," her mom tells PEOPLE.
The difference is, the tot actually got to rub shoulders with Miley Cyrus, who plays the Disney Channel heroine – because Shields guest-starred on an episode in which she plays the title character's deceased mom, who comes back from the dead to comfort Miley/Hannah.
Rowan, whose dad is Shields's husband, TV writer-producer Chris Henchy, "was so excited she got to go to a taping of it," Shields, 42, said at a dinner hosted by Julianne Moore and Coach leather goods president Reed Krakoff for artist Hunt Slonem and his book Pleasure Palaces.
But, as the cameras turned at the taping, Shields's line of dialogue was, "It's okay, baby girl" – which just happens to be the private term of endearment Shields uses for Rowan.
To make matters worse, Rowan witnessed her mom give a hug to Cyrus, prompting Rowan to stand up in the studio audience and shout, "Nooooo ... That's my mama for real life!"
Only leave it to mom to make all things right. Come a break in the filming, Shields was able to bring Rowan down to meet Cyrus in person to hug it out.
"Miley was so-o-o sweet," said Shields, who added that the 14-year-old star told Rowan, "It was so nice for you to let me borrow your mom for today."
Responded Rowan firmly, just so there was no mistake about it: "It's okay, but she's my mama for real life."