Reprinted from yesterday's late editions.

Another member of the Carter Pool for Ceremonial Occasion came forward to represent the President Tuesday night at the Mexico embassy reception for the President of Mexico and Mrs. Jose Lopexillo.

Everybody knows Jimmy's a working person," said President Carter's sister, Ruth Carter Stapleton. "It's to be his policy that he entertains and then that's it. His sons and daughter and the rest of us will be doing the rest, just like we did campaigning."

Mrs. Stapleton had attended the State Dinner at White House Monday night but her husband, a veterinarian, had not because, as he said, I work for a living and I'm self-employed."

"But when the Stapletons got their Mexican embassy assignment from the Carters Tuesday morning he came to Washington to join her. Why was it a matter of dispute between them?

"When the President tells him to come, he comes," said Mrs. Stapleton.

"No, I don't," said Stapleton. "When the President's sister tells me to come, I come. I'm not married to Jimmy."

Mrs. Stapleton stuck to her theory. "From now on if I need a new dress I'm gonna tell the President to tell him," she said.

Vice President and Mrs. Walter F. Mondale also attended the reception for about 1,000 guests.

There's never been any set rule about which top American official comes to "reciprocal" entertainment by a state visitor, a State Department protocol officer confirmed, and in recent administrations either the President, the Vice President or the Secretary of State has usually gone.

The Carters also will be supplying a member of the family of such occasions, and the Stapletons have been asked to work the Canadian state visit next week but have not decided for sure yet. Jeff Carter, the President's son, and his wife were supposed to do the Mexican reception Tuesday night, Mrs. Stapleton said, but they were too tired and "I wanted to. I met the Mexicans at the inauguration and loved them."

Does this arrangement mean that the British embassy, for example, if their queen were to return for a visit, might draw the President's brother, Billy Carter, to meet her? "Probably not Billy," said Mrs Stapleton. "Billy has his own schedule. He is out speaking three times a week now."

The Mexican reception was a lavish one, and although it had been termed "informal" women dressed up for it more than anyone had the previous night at the White House black-tie dinner.

Featured on one of the enormous buffet tables were crossed Mexican and American flags made of fruit. The Mexican one was a reasonable facsimile with red strawberries, white coconut and green melon balls. But the American was an odd shade as green melon balls were used for the stars and pineapple for the white stripes.

On another table blue-colored water splashed on fountains that had whole lobsters hanging over the sides like sea horses.

There were several musical groups playing, including "Los Tiempos Pasados," 12 Mexicans and Americans who played medieval and Renaissance music on instruments of the time. The First Lady had admired this group when she was in Mexico for Lopez Portillo's inauguration and they were brought to Washington with the hopes of playing at the Whit House dinner.

Since this didn't work out, Mrs. Carter requested them Tuesday afternoon at a tea she gave for reporters who cover East Wing White House events. The group also presented her with a shocking pink poncho at the tea.

Mrs. Lopez Portillo has been trying to interest Mrs. Carter in her project of turning border towns - which she called "cities of vice" - into cultural centers. They discussed the project Tuesday morning when they toured the National Portrait Gallery and Mrs. Carter expressed interest but didn't commit herself.