A neatly dressed woman in her late 30s has been living in her late-model Plymouth Duster near Washington Circle for the last month or so, puzzling dozens of nearby residents and workers who have seen her daily or talked with her.

Since she took up resident in a parking place next to the Park Laundry at 2423 Pennsylvania Ave. NW, the woman has accumulated at least 12 parking tickets on her car, which bears Pennsylvania license plates.

"She just reads magazines and smokes cigarettes," said Kevin Whitener, a cook at the Washington Circle Drugs luncheonette across the street from the green-and-white car.

For the most part, the woman refuses to talk with virtually all merchants and residents who work and live in the 2400 block of Pennsylvania Avenue. When a reporter attempted to interview her, she simply shook her head and walked away.

During most of her month-long encampment, the woman has remained in her car, to the point of sleeping there. As temperatures climbed in recent days, she moved out to a nearby park bench. There, she continues her cigarette-smoking, magazine reading routine.

The car's interior shows signs of being lived in. Yellowed newspapers and soiled styrofoam coffee cups are scattered over the floor of the front seat area, and good-sized wardrobe hangs form the hooks on the sedan's cealing.

Several magazines, newspapers and books, all of which have pictures of various Kennedy family members, line the car's interior.

Among some of the woman's belongings are a People magazine issue the cover of which features Sen. Edward M. Kennedy (D-Mass.), a biography of Jacqueline Kennedy Onassis, a paperback with a black-and-white picture of Sen. Kennedy on the back cover, a poster of John F. Kennedy, and a Parade magazine issue whose cover bears a portrait of the 35th president.

B.B. Schlegel, a District meter maid who issued seven parking tickets to the woman in the last week, said, "When I asked her why she doesn't put money in the meter, she told me Senator Kennedy told her she didn't have to. She then proceeded to tell me that Senator Kennedy was her lawyer."

A spokesman for Kennedy said she did not know of any contacts with the woman. "We get a lot of people who seem to have a Kennedy obsession," said Melody Miller, an aide for the senator.

One of the few people to have spoken with the woman, Whitener said she initially ate several meals at the luncheonette but has not returned for three weeks.

"She used to come every day about a couple of times for breakfast, lunch or dinner," Whitener said. "One Sunday night she was in here asking about hotels.I think she's on a budget, because she was asking where it was cheap to live around here. She's no bum - she's got some nice clothes and a nice car."

"She goes through a daily ritual," says John Paterson, an employe at Federal Supermarket, a grocery across the street from the woman's car. "She reads all the time, and she gets out of her car about three times a day."

According to Patterson, the woman initially fed money into the parking meter next to her car. She ceased that practice about two weeks ago, Patterson said. "The meter maid will ticket her car while she is sitting in it," he said.

Before she parked on Pennsylvania Avenue, the woman had camped out on the 2400 block of M St. NW, where she followed the same routine for two weeks, witnesss said.

During her stay on M Street, the woman occasionally used the rest room facilities of a nearby Gulf station to change clothes. "She came here twice to my knowledge," said Reginald Martin, owner of West End Gulf.

Metropolitan plice and the D.C. Department of Transportation show no record on the vehicle or the woman. However, the Department of Transportation computer does not show information on any outstanding parking tickets unless they are 15 days old, said Anita Downs, assistant chief in the department's processing division.

As the thermometer dropped slightly yesterday, the woman was looking at a District road map yesterday afternoon. When a reporter asked if she was planning to move on, she just smiled and returned to her map.