Del. Mary A. Marshall (D-Arlington) likes to refer to herself as a "blue-eyed, curly haried, mental-health-loving mother of three."

But don't let the mokiker fool you. Marshall's self-effacing manner, she says, increases her effectiveness as a lawmaker.

"Saying you're a 'mere housewife' is the equivalent of calling yourself a 'simple country lawyer,'" says Marshall, drawing a parallel to Watergate investigator Sam J. Ervin. "It's a non-threatening phrase that may, or may not, indicate you know what's going on."

One of eight women in the 140-member General Assembly, Marshall says her self-imposed occupational label came in handy when she was trying to win passage of a controversial measure increasing the rights of small, independent gasoline dealers in 1973.

"One reason that bill went through was because the big oil companies never thought a housewife from Arlington could get it through," she says. "By the time they figured it out, it was too late."

With the approach of the final days in which the House of Delegates can act on bills filed by members, the 12-year legislative veteran finds herslef in a race against the clock to get all of her bills out of committee by this weekend's deadline.

Her calendar yesterday showed at least eight vital meetings of committees, subcommittees and other groups, starting at 7:30 a.m. and extending into the night. Some ran concurrently, leaving Marshall no choice but to race back and forth between the two legislative buildings in Richmond.

If all were to go without a hitch, Marshall said, she sould have had ample time to stump for her plans to get aid for residents displaced by condominium conversions, institute a state program of yearly car emission inspections and pass a package of what she calls "tiddly" enabling legislation for Arlington County, including one that would let county officials mail notices to citizens about certain land-use changes.

But there was far more likelihood, she said, that she would spend some time cooling her heels, waiting for the legislative panels to get around to her measures.

"You've got to have a sense of humor about all this," stresses Marshall, punctuating the remark with a chuckle. "If you come here interested only in issues, with the intent of changing the government, you won't last long. If you enjoy the show, you'll do much better."

Under lying her work these days, Marshall says, are efforts to get approval for Metro financing (which she called "all three" of her top three goals for the 1980 session) and ratification of the Equal Rights Amendment.

The ERS's faltering fortunes have been the biggest disappointment for Marshall, who says she has "tried everything" to blast the controversial measure through the House. Now, she says, the ERA is definitely dead in Virginia. The measure was defeated in the Senate Tuesday.

Marshall, a woman who avoids annoying more conservative colleagues by speaking in a stage whisper when she calls herself a "liberal," says the moral of the ERA fight is that "change comes hard in Virginia."

"We had a glorious past, and then in 1830, (when Virginia switched its economic base from tobacco farming to cotton,) things started to go downhill. So Virginians have not always viewed change as being for the better".

The resistance has persisted into the present, with the state lagging 20 years behind the rest of the nation in ratifying suffrage for women, and refusing outright to approve constitutional amendments for direct election of U.S. senators and a federal income tax, among others.

Included in Marshall's top goals for the 1980 session is her car emissions bill, which is given little chance of passage by other legislators. The measure, opposed by auto clubs and others would require motorists to have their car emission systems checked every year and to make repairs up to $75 if necessary.