The mailbox for the penthouse of an aging eight-story building on Chicago's South Side carries a single name: Khalilah Ali. Upstairs in a four-bedroom apartment, the lady of the house, born Belinda Boyd, lives with her four children. "My interest now is in the Nation of Islam," she says. "Not in boxing. And not in my husband."

Her husband is Muhammad Ali, heavyweight champion of the world, whose name graces the mailbox of an apartment a mile away.

Since their public feud in September in Manila, site of Ali's successful defense against Joe Frazier, Mr. and Mrs. Ali have fallen on marital hard times. Today Khalilah (her Muslim name), a striking, powerful woman—5'10½", 160 pounds—is forging a new life for herself. She works as a publicity agent and photographer at Bilalian News (formerly Muhammad Speaks), the official Muslim newspaper. Last week the paper ran a bylined picture essay about Muslim mothers shot by Khalilah, "making me," she says proudly, "a bona fide photojournalism"

Belinda, 25, rarely gives interviews, and is reluctant to discuss Ali. "I don't like to talk about marriage," she says. "That's not my interest now." In Manila tensions between the two of them erupted into a loud hotel room quarrel and Belinda flew home almost immediately. The cause was Ali's perpetually roving eye. "I knew that this was going to happen before I married him," Belinda admits. At the time Ali was paying court to mystery woman Veronica Porche, a former L.A. beauty queen.

He met Veronica in September 1974 at the Salt Lake City airport. After a long, intimate chat, the smitten Ali invited her to meet him in Zaïre, where he was scheduled to fight George Foreman for the championship. Taking him at his word, Veronica flew to the African nation. "At first Belinda thought Veronica had come to Zaire for someone else," said a friend of Ali's. "But when she discovered the truth, there were fireworks. They had a terrible fight and Belinda was ready to go home. Ali would have let her go, too. He can be cruelly stupid when he's angry. But his people convinced her to stay on through the fight."

Belinda's subsequent reconciliation with both Ali and Veronica seemed convincing. According to some reports, Belinda had dutifully agreed that Ali could exercise his Muslim option to take a second wife (he is permitted four). Since then, Ali's aides have explained ever-present Veronica as a traveling companion of Belinda's; a cousin of Ali's; a babysitter; and a close family friend. She has been introduced by friends as "Veronica Ali," and Belinda once called her "Ali's other wife."

Belinda's own marriage to Ali was arranged in 1967 by her Muslim parents in old-country fashion. "I wasn't but 17," she remembers. "He saw me when I was a junior at the University of Islam [a combination grammar and high school]. The next year he came back and began questioning my mother and father." The couple never went out; Ali just came to dinner. "I really didn't care," she continues, "I figured he was tall enough and good-looking enough. I didn't want to say yes or no. He just told me, 'You are going to be my wife' and it was arranged."

She was unenthralled. "I was a tomboy," she explains. "All I cared about was my horses." Indeed in her apartment today are many equestrian ribbons but only two minor boxing trophies. Nonetheless, Belinda and Ali were married at her home in August that year by a Baptist minister. (The Muslims did not have their own ceremony then.) Love later blossomed and they had four children, Maryum, 7; twins Jamillah and Rasheda, 5; and Ibn Muhammad, 3 ("I pray to God I have as many as I was put on earth to bear," she says). When Ali regained the championship, their cup overflowed. They bought—and still own—his and hers Rolls-Royces. She fed him Wheaties for breakfast.

Belinda resisted having servants. "You grow up learning how to cook, sew and take care of children," she says. "Where your family is concerned, work is just love made visible."

In her new career, Belinda receives no salary. She puts in a 40-hour week and recently flew to Los Angeles to cover a fashion show. She believes her success will demonstrate that Muslims too are interested in women's progress. "It's liberation in a way, but not 'masculinization.' "

Although she has a third degree black belt in karate, Khalilah professes to be appalled by boxing (and had no plans to watch TV as Ali defended his crown last week against Belgium's Jean-Pierre Coop man). "Boxing is cruel," she says. "Two people fighting each other, and it's billed as entertainment! Can you believe anyone would like something so bloodthirsty?"

Yet there is little passion in her voice. Nor does she seem disturbed by mention of a possible divorce from Ali. "Nothing upsets me anymore," she says with a shrug. "Nothing will anymore. I'll tell you that."