A 43-year old woman who represented herself as a prominent socialite in Alexandria was sentenced to five years in prison yesterday for stealing nearly $10,000 from an Old Town real estate firm in 1982.

Susan L. Benson, who pleaded guilty to grand larceny, had crisscrossed the country leaving behind 20 aliases, eight felony convictions and five marriages before she came to Alexandria, assistant prosecutor Richard Mendelson told Circuit Court Judge Donald M. Haddock. He said Benson told Alexandrians she was "Amanda Rossignol," an heir to the Rossignol ski manufacturing fortune.

"Everyone believed her. She was so personable. She seemed like she knew everybody," Mendelson said.

Hired as a secretary in the Macklin-Hansen Real Estate Corp. and Crilley Ltd. Partnership on N. Lee Street in June 1982, Benson had worked there two weeks when she wrote her own name as the payee of two company checks, one for $8,547.97 and the other $1,408.61, according to the indictment against her.

After depositing half of the money, and taking the rest in cash, Benson left town, according to court testimony, and last September was picked up in Northern California by a traffic officer who found she was driving a stolen car. Before coming to Alexandria she was first sent to Fairbanks, Alaska, where she pleaded guilty to five counts of forgery and was sentenced to 30 months in jail, Mendelson said.

Haddock, who suspended 10 years of a 15-yeear sentence, said Benson will return to Alaska and serve herr time there before she begins serving her Alexandria sentence.

Defense attorney F. Andrew Carroll argued that though his client "had done many awful things," she had recently demonstated many "positive steps"while in the Alexandria jail, including crotcheting warm socks for elderly women in nursing homes.