NEW YORK — Aaron Conley is an old hand at show biz. In February, he will celebrate his 300th performance in a Broadway musical. Hanging out backstage with the Hollywood director Spike Lee and entertaining guests at a book party for Andre Leon Talley, Vogue's editor at large, are all in a week's work for Conley.

But Conley is 11, so besides making sure he doesn't miss his cue as Young Simba in "The Lion King," he's got other things to worry about — like doing his homework and cleaning his room.

Conley is one of dozens of children who perform professionally in Manhattan. They are accomplished actors, singers and dancers who take great pride in what they do. But balancing the demands of an artistic career with growing pains isn't easy.

"They are performing a professional job and are expected to maintain academic standards. That's like having two jobs," said Willie Boston of the Actor's Equity Association, the union of theater actors and stage managers. "Plus, they're also kids, so my hat is off to them."

In Conley's case, that respect seems doubly earned. Not only does the sixth-grader from West Point, Miss., contribute to his family's income, as many child performers do, but he is, in fact, the sole breadwinner of the household.

Oretha O'Neal, a single mother who has raised Aaron and his sister, said that after leaving behind her network of family and friends in Mississippi, she found it impossible to keep a regular job while shuttling her son back and forth to auditions, rehearsals and shows.

Conley, whose wide smile reveals a gap between his teeth and who likes to wear his Yankees cap sideways, said he enjoyed being able to support his family. And O'Neal wants to make sure her son, whom she calls "Mr. Aaron," knows about checks and balances.

"He needs to learn how to spend the money, so I show him the pay stubs, tell him what he's taxed for, how much goes into his 401(k) plan," she said.

Apart from managing his income, Conley also has to stay focused on the job itself: doing cartwheels across the stage, belting out "I Just Can't Wait to Be King" astride a giant bird and mourning the death of his lion father — all in front of an audience of hundreds.

The children "carry the entire first act," said Niki White, the child wrangler for "The Lion King" who supervises young cast members behind the scenes. "If they were ever to slack off, it would affect everybody on stage. It's a huge responsibility."

Alan Simon, president of On Location Education, the country's premier teaching service for child actors, said this responsibility added a kind of pressure not usually experienced during childhood.