WASHINGTON — The photographer asked the new congresswoman to turn and walk toward him so the ornate Speaker's Lobby would be in the background.

Suddenly, a Capitol Hill policeman rushed up to inform her that shooting pictures in the meeting area just off the House floor was strictly forbidden.

Then the security guard spotted the gold lapel pin that House members wear and changed his tune.

"Oh," he said soothingly, making a mental note of the member's face, "I didn't mean to interrupt."

Rep. Juanita Millender-McDonald, California's newest member of Congress, did not seem to mind a bit. Having been sworn in only three days earlier, she could hardly be expected to know all the arcane lore of the House--nor could everyone know her.

She is filling out the term of former Rep. Walter R. Tucker III, who resigned late last year after a conviction in a bribery scandal.

For now, Millender-McDonald is focusing on the fundamentals, such as navigating the Capitol's subterranean passageways and organizing her Washington office.

Since her arrival early last week, a frazzled team of three staff members has been fielding phone calls, tending to visitors and feeding the fax machine.

Plaques and citations dot the walls and magazines stuff the racks, but the modest warren of offices definitely has that just-moved-in-look.

"I love it, I think it's really nice," Millender-McDonald said in a forgiving appraisal of her fourth-floor suite in the venerable Cannon Office Building.

It is not as grand as the Sacramento digs she had occupied as a member of the California Assembly.

"A constituent came [to Washington] to visit and remembered the suite I had when I was chairwoman of the Revenue and Taxation Committee," Millender-McDonald recalled brightly. "But I'm not chairwoman of the [House] Ways and Means Committee, so I can't get an office quite that large."

Not that she is complaining, mind you.

"I'm very excited about being here," Millender-McDonald said. "It feels good coming to even a greater [legislative] body . . . to help the people of the region and the people of my district."

Surrounded by more than a dozen family members, including her five children, she was sworn in by Speaker Newt Gingrich (R-Ga.). Afterward, her fellow Democrats welcomed her warmly.

House Minority Leader Richard A. Gephardt (D-Mo.) hailed her as a "woman with almost unlimited interests and abilities" and a "sage and experienced legislator."