Six years ago, Adele Barrett was a suburban housewife, with no formal training in business or economics.

Today, she is an Assistant Vice President of the Washington office of Kidder, Peabidy & Co., one of Wall Street's prestigious firms.

More important, Barrett has become one of the most successful individual stock brokers in the metropolitan area, with a volume of business exceeding $200,000 a year.

At Loeb Rhoades & Co. Inc., where Barrett worked for two-and-a-half years before joining Kidder last November, her sales volume during the first year on the job ranked her 67th out of more than 900 Loeb Rhoades sales professionals in all the firm's offices. When she departed, her ranking was 43rd.

In the Washington area last year, she was the top broker in all firms for sales of deferred annuities - an investment program now under attack by the Carter administration. The interest on deferred annuities builds up but is not taxed until the investor begins to get annuity payments.

Barrett has accomplished all this, in the words of her boss, because she's one of a "new breed of broker." Kidder, Peabody office chief Robert J. Kelley said, "Lots of brokers don't want to lock up investments, because that ties up future commissions."

But Barrett, he said, is "not really interested in writing a (sales) ticket. I've never seen more personal interviews with investors. She tries to work out a plan that can't hurt anyone."

In an interview, Barrett attributed this desire to a former investment by her husband, a successful businessman here. He bought some stock and saw his investment double. But he sat on it and no broker advised him to sell, before the gain was wiped out.

"Most people are interested in making money," she said. Her philosophy as a broker is to help them meet that goal by telling them not to be "greedy" after a stock investment increases in value, to sell at that point and invest in something else.

Other than reading newspapers and watching the market over the years, Barrett had no knowledge of the securities business when she applied for a job at a brokerage firm six years ago. Her first employer told her to study the National Association of Securities Dealers manual and pass the NASD exam. She passed that test and also the licensing exam of the New York Stock Exchange.

Now she works from 9:30 a.m. to 6 p.m. or later on weekdays, makes telephone calls and conducts annuity interviews at nights, and still manages to have a family life.

Most of her clients are business people who "don't have time to watch the market, I watch it for them," she said. She welcomes clients with at little as $2,000 to invest, but has some persons with portfolios worth half a million dollars or more.

"Every client is important . . . the smaller ones helped me get to the bigger ones," she noted.

For the variety of clients she interviews before engaging in any investments for them, she suggests a variety stocks, options, tax-free bond, deferred annuity, Government National Mortgate Association or tax shelter investments. She does not handle commodities, calling oversight of that market sector a "seven-day job" by itself.

Depending on individual goals of income or long-term investment, Barrett suggests that some persons invest entirely in stocks and that others stay away from equities altogether.

Sales of deferred annuities continue at a rapid clip, although each client who now enters such an investment signs a disclaimer that points to the possibility that interest income from such accounts could be taxed under the administration's tax "reform" proposals.

"No one knows" where the bottom to the current, sagging stock market is, Barrett stated. "There are too many uncertainties . . . the impact of the coal strike has not been felt yet . . . we're due for some technical rallies." But further declines in popular stock averages should be expected, she added.