Q. Give me some information on Robin Mattson, who plays Gina Timmons on "Santa Barbara." - C.C., Rapid River, Mich.

A. Mattson, 35, is a native of Los Angeles. She started acting at 6 in commercials, and at 9 did her first feature film, "Namu, the Killer Whale." She studied at Santa Monica (Calif.) City College while continuing to act in TV and movies. She's a soap veteran as Hope Bauer in "The Guiding Light," Delia Ryan on "Ryan's Hope" and Heather Webber in "General Hospital." She joined "SB" in 1985.Q. Michael Knight, who is Tad Martin on "All My Children," was on leave of absence. What happened? - H.D., Arleta, Calif.

A. Knight broke his collarbone in a fall. Terrell Anthony, who played Rusty Shayne on "The Guiding Light," was Knight's "AMC" sub.

Q. I just saw "Heathers" starring Christian Slater. Give me some background on him. - K.B., Macon, Ga.

A. Slater's 21, son of actor Michael Hawkins and casting director Mary Jo Slater. Mom got him his first acting job, when he was 7, in the soap "One Life to Live." He's been at it ever since, on stage, screen and TV. His first movie was "The Legend of Billie Jean" and his big break, "The Name of the Rose" with Sean Connery. He's done other soaps, "All My Children" and "Ryan's Hope" twice, the second time a regular role as D.J. LaSalle. His other movies include "Tucker" and the current "Young Guns II" and "Pump Up the Volume."

Q. What has become of Mary Badham, the little girl who played Scout in "To Kill a Mockingbird"? - R.A., W. Bloomfield, Mich.

A. Badham's a big girl now, 38, married, a mother and manager of a Virginia store. She did two more films after 1963's "Mockingbird," "This Property Is Condemned" and "Let's Kill Uncle," both in 1966.

Q. I've looked everywhere for this. In how many movies did John Wayne get killed, and name them. - F.T., Chicago.

A. According to a list compiled several years ago by People magazine and the Duke's fans, he died in 10 movies: "The Flying Tigers," 1942; "Reap the Wild Wind," 1942; "The Fighting Seabees," 1944; "The Wake of the Red Witch," 1948; "Sands of Iwo Jima," 1949; "The Sea Chase," 1955; "The Alamo," 1960; "The Man Who Shot Liberty Valance," 1962; "The Cowboys," 1972; and "The Shootist," 1976.

Q. Was Linda Evans ever married to John Derek? Who were his wives other than Bo Derek? - M.U., Orange, Calif.

A. Evans was Mrs. Derek No. 3 and the wife Derek dumped to marry teen-ager Mary Catherine Collins, whom he renamed Bo Derek in 1977. Starlet Patti Behrs was the first Mrs. Derek, 1949-55, mother of his two children; Swiss actress Ursula Andress was next, 1957-65; Evans lasted 1965-75.

Q. Tell me about the great character actress Beulah Bondi, where and when she was born, when she died, information on her career, relatives I can write to because we may be related. - M.B., Lafayette Hill, Pa.

A. Actress Bondi's original name was spelled Bondy. She was born May 3, 1892, in Chicago. An actress from the time she was 7, she did made her Broadway debut in 1925 and her move debut in 1931 in "Street Scene." She had two Oscar nominations, "Gorgeous Hussy," 1936, and "Of Human Hearts," 1938. She retired from the movies in 1963 but still did TV and theater. She won an Emmy in 1977 for "The Waltons." She never married. She died in 1981.

Q. Is it true that Rue McClanahan suffers from claustrophobia that causes problems with her acting on a small TV stage?

A. Claustrophobia hasn't been a problem for McClanahan as the frisky coquette Blanche Devereaux on NBC's "Golden Girls," but it did affect her during filming of her USA Cable movie "After the Shock," about the San Francisco earthquake last year. She played Sherra Cox, who was trapped for hours in the rubble of her collapsed apartment building. Production for the movie, to be shown Wednesday, became an ordeal for McClanahan, who felt sick and panicky whenever piles of fake debris covered her for key scenes. "The real Sherra Cox told me that she didn't feel panic," McClanahan says. "I think that woman must have been in a state of grace."

Q. Is Crispin Glover, the actor who stuffs cockroaches into his shorts in David Lynch's film "Wild at Heart," really as weird as his reputation?

A. Glover, 26, concedes he's worried about being misunderstood, but he has a penchant for attracting attention with his quirky behavior: His car is such a distinctive style that he doesn't want it described in print, for fear of drawing obsessed fans; and on "Late Night With David Letterman" three years ago, he almost knocked out the host's teeth with a karate kick; and he has republished a century-old book, "Rat Catching," adding pictures of mutilated vermin. "People call up and talk to my answering machine," says Glover, who's appeared in "Back to the Future" and "River's Edge," "and I can tell they're having a good time calling this person that they think is pretty wild."

Q. Just how many people is Wilson Phillips?

A. Pardoning the grammar, three. The pop group comprises Chynna Phillips, 22, child of the Mamas and the Papas' John and Michelle Phillips; and Carnie and Wendy Wilson, 21 and 20, daughters of the Beach Boys' troubled genius, Brian Wilson, and his ex-wife, Marilyn, who sang with the '60s vocal trio the Honeys. Wilson Phillips began four years ago. "Our three-part harmony just felt so natural," recalls Wendy. They spent the next couple of years developing their style and considered such names as Sound Thoughts, Zen Girl and Ladies First. Of their chosen moniker, Chynna notes, "most kids today have no idea what those names mean . . If you say `Phillips,' they'd think screwdriver or milk of magnesia."

- Send your questions to Celebrity Questions, Detroit Free Press, Detroit, Mich. 48231. Sorry, the huge volume of mail prohibits personal replies.