During shooting of an outdoor scene for "Hairspray" last summer, it suddenly started raining down hard on the actresses' 1960s bouffant hairdos. Since it was also 4 in the morning, almost all the cast and extras lobbied to be allowed to go home.

The exception was a 4-foot-10 ingenue. Her name, Nikki Blonsky, was unknown a week ago, but is all over the news since the movie's release.

"I turned around and I was like, Guys, we are making a movie. You know how amazing that is?' " Blonsky said. "Everyone was just looking at me, but they were used to me by then. Because I know what it is like to be working at an ice cream store, and now I know what it's like to be on a movie set, and you have to be very grateful for every day you have."

Blonsky's enthusiasm never once dampened during the six-month shoot in Toronto, which substituted for the streets of Baltimore, where John Waters set his story about plump teenager Tracy, who realizes her wildest dream when she's chosen to be on an "American Bandstand"-like '60s TV dance show.

Meeting Blonsky, an 18-year-old making her professional debut, the temptation is to call her Tracy because their career trajectories are almost identical.

Two short years ago, every day after school, she could be found scooping ice cream at Cold Stone Creamery in Great Neck, N.Y.

Blonsky read online about a nationwide search for an unknown to play Tracy. Although her experience was limited to high school theatrics, she felt compelled to try out.

When Blonsky saw "Hairspray" on Broadway, "it was the first time that I ever saw another person that I totally identified with on all levels, because she was a 17-year-old girl with a big dream who wasn't afraid to be herself and didn't apologize for herself."

Like the fictional Tracy, Blonsky has always been large, but wasn't made to feel bad about it. Blonsky put together a tape of herself performing "Good Morning Baltimore," "You Can't Stop the Beat" and other songs from "Hairspray."

Director Adam Shankman has been quoted as saying, "Once I saw Nikki's audition, I immediately put her on my list."

It came down to four girls and then, finally, to one.

Blonsky is back living with her parents — her father works at the water pollution control department, her mother is an elementary school aide — until she sees where "Hairspray" takes her.

Her hope is that if the musical is well-received, "it will open doors for many more heavyset actresses," she said. "I mean, why can't a plus-size girl be the love interest and get the guy? What's wrong with that? It happens in real life."

Blonsky says her agent has been receiving lots of scripts.

Is there one part she's dying to do? "I'd love to play Mary Poppins if they ever do a remake," she said.