The reality is that Andrea's lucky they didn't put HER in the featured category, since she was a child. That was the trend back then. Just look at Tatum O'Neal, who practically never left the screen in Paper Moon, but won Best Supporting Actress at the Oscars.
Initially child actors were given "special" awards. They weren't even competing in the major categories (see Judy Garland in Wizard of Oz, Shirley Temple, and Margaret O'Brien in Meet Me in St. Louis). Then they stopped giving the special awards, and child actors basically ended up with nothing. Then along came Patty Duke, who at 14 was the youngest Oscar-winner in a competitive category ever in 1962. Patty wasn't even nominated for a Tony Award at 12 for the same role (Helen Keller in Miracle Worker).
When Andrea McArdle got a Best Actress nomination, she was the youngest performer ever nominated in a leading category. I think she still holds the title (as far as leads go). So she was a "first." The typical situation would have been either not to nominate her at all, or push her into the featured category.
The other criteria with Tonys is billing. It still is. If you're given "star billing," you're in the leading category. If not, no matter how big the role, you're in the featured category. That's why people like Yul Brynner in the King & I, Barbara Cook in Music Man, and Isabel Bigley in Guys & Dolls all won "featured" awards for leading roles.
Producers have to petition a committee if they want actors to be considered in a different category, and they may or may not be accepted as such. Both McArdle and Loudon had star billing in Annie (so did Reid Shelton). So they were considered in the leading categories by default.
I also think the role of Miss Hannigan is pretty large for "featured." She has almost as much stage time as Annie. They did the right thing with leaving it all alone. And as a result, McArdle became the youngest ever nominated in a leading category. Still a great honor to this day.
"Jaws is the Citizen Kane of movies."
blocked: logan2, Diamonds3, Hamilton22