Maybe Richard Nixon put it best for both Betty Ford and Rosalynn Carter when, flying off in a helicopter bound for Air Force One and Anwar Sadat's funeral in Cairo, he looked down at the White House and said, "I kind of like that house down there, don't you?"

Telling that story yesterday was Rosalynn Carter, one of two former first ladies speaking in separate settings here this week about life outside the White House, Reaganomics, presidential china, ERA and a history-making trip to Egypt that brought former presidents Nixon, Gerald Ford and Jimmy Carter together for the first time.

Rosalynn Carter, 54, in a light-brown skirt, white blouse and tweed vest, talked with a small group of reporters at the apartment of Mary Hoyt, her former press secretary. She was in town with her husband to attend the National Mental Health Association's tribute to Averell Harriman. Betty Ford, 63, wearing a white wool dress, was interviewed in her hotel room Monday after joining a rally urging passage of the Equal Rights Amendment.

Both looked slender and joked about keeping fit, offered updates on their families and voiced some common concerns about programs they supported when their husbands were presidents and still support today.

A sampling of those conversations:

On the need for new White House china.

Rosalynn Carter: "It's always a temptation for first families to buy china. I'd liked to say, 'This is Rosalynn and Jimmy Carter's china,' but I didn't think we needed it." But at another point: "I thought we were going to be there a long time and I didn't think I had to rush."

Betty Ford: "I happen to know the White House needs new china." But at another point: "I happen to like to mix china patterns. I do it at home."

On the need to fix up the White House, and the Reagan refurbishing.

Rosalynn Carter: "I think it was a good excuse to do something. The White House was beautiful. I loved it. The upstairs was comfortable and cared for. They always did things floors, rewiring, painting when we were gone, or at Camp David." And a little later, talking about returning to the White House last week for the first time since they left last January, she said, "When we went into the Blue Room, somebody came over and said, 'What do you see different about this room, Mrs. Carter?' And I had been looking for something different but I hadn't seen anything. Then Mrs. Reagan told me the sofa was different. Not long before we left we acquired the original sofa that was in the Blue Room, and she had had it covered."

Betty Ford: "The White House went through a stressful period -- just like the executive branch of government -- where it really needed some work. But it's wonderful what Nancy Reagan has done with private funds. The government needs all its money."

On three former presidents traveling together to Cairo.

Rosalynn Carter: "It was a little bit tense with Ford for awhile but as soon as we got off the helicopter at the White House Nixon started joking . . . He said, 'What color are your eyes, young lady? They're hazel,aren't they? They match your dress. I notice things like that.' . . . On the way back Ford could not have been nicer. He insisted we come in to the presidential compartment and eat with him. We talked about the library."

Betty Ford: "I'm sure for a little bit it was somewhat uncomfortable . . . But he said it was a very warm, friendly trip, which perhaps mended a lot of barbs made during the last campaign because President Ford was rather critical of President Carter for President Reagan."

On making the trip:

Rosalynn Carter: "President Reagan invited all the former presidents and their wives." And later, speculating on why Pat Nixon hadn't gone to Cairo: "Nixon said they had been living in a hotel for five weeks and were moving. He said the carpet was supposed to come the night before he left but it didn't, and that he had thought he was going to eat at home but then had to go back to the hotel."

Betty Ford: "I sort of toyed with the idea of going but nobody made the suggestion that I go."

On Jihan Sadat.

Rosalynn Carter: "When we sat down she shifted chairs to where he President Sadat had been sitting. She looked over and she started crying."

Betty Ford: "She could be a role model for me . . . Would that I could do for American women as much as she has done for Egyptian women."

On a husband's adjustment after the presidency.

Rosalynn Carter: "We had not heard from the White House though Jimmy tried to get a briefing for months. One morning I heard on television that Nixon was helping Mr. Reagan. The White House said it wasn't true, that it was just part of the regular briefing they gave former presidents. So I said, 'Jimmy, we ought to call them and tell them that this former president hasn't had a briefing.' "

Betty Ford: "I'm talking to him about helping with ERA and he's very supportive. I hope that I'll do better on this than I did on getting a woman in the Supreme Court. I said maybe I didn't start soon enough then. Now I'm going to try to work on him because I think he could be a big asset."

On the Equal Rights Amendment.

Rosalynn Carter: "I have done nothing on ERA." And a little later, "If there is anything I can do to help it pass, I'll do it . . . He Jimmy Carter would, too."

Betty Ford: "I'm committed to the passage of the Equal Rights Amendment, would like to feel I helped -- and I don't have a lot of time left, not as much as I did 20 years ago." At another point: "I haven't talked to Mrs. Carter about it and probably I should. She could be very helpful. Then, if two former first ladies could get two former presidents, well, stranger things have happened. This weekend, for instance, who would imagine former President Ford and former President Carter would be walking with their arms around each others shoulders?"

On Reaganomics.

Rosalynn Carter, talking about its effect on the Mental Health Systems Act, which she worked on for two years: "Totally . . . It's been replaced with block grants. I just think it's incredible, a tragedy, and that it's going to cost the country untold human lives."

Betty Ford: "Everybody has his own cause, whether it's the Endowment for the Arts, which I always was very interested in. I think the idea was across-the-board budget cuts for everything which probably will have to be relooked at. Only living with it probably will show the need for adjustment."

On family.

Rosalynn Carter: "Amy had a date for the homecoming dance. I said, 'Amy Carter, you better be glad you've got Secret Service agents. Otherwise there is no way I'd let you have a date at age 13.' . . . Jimmy's mother had a terrible time, broke her hip, fell three times, hurt her spine, had a malignant tumor on her breast . . . then the other day went out and caught a two-pound bass."

Betty Ford: "Mike is at Wake Forest University, assistant to the dean . . . Jack has to make up his mind whether to run for California state comptroller or for one of the new congressional offices . . . Steve is a soap opera actor with fan mail, a following, and his part is growing . . . Susan is a wonderful mother. She's matured so."

On keeping busy.

Rosalynn Carter: "I'm writing my book due at the publisher, Houghton Mifflin, by Aug. 15, 1982 . . . My writing style is questionable . . . Jimmy works eight to 12 hours a day on his book. I can't do that. Pears get ripe and I want to make pear relish . . . I have a forum. I get invitations to do things. I have accepted no invitations except a citizen's-group fund-raiser and the Georgia Mental Health Association."

Betty Ford: "I'm home one or two days a week . . . But there's a whole new impetus to ERA. We need to not only give our voice but to lend our efforts and time. Women are giving up good positions and going on leaves of absence, young people in their senior years in high school are taking leave to work on it . . . There isn't a big ERA chapter in Palm Springs, no, but there are those of us who feel more akin perhaps to the average woman, the average family, because of our backgrounds. Now we feel we're privileged and want particularly to help causes that will help the average family. It's so changed, you know."