Former first lady Betty Ford fielded questions at the Washington Press Club luncheon yesterday on everything from the recent emergence of Richard Nixon to the problems of handling intimate marital relations under the circumstance of mastectomies, arthritis, or alcoholism. She has experienced all three.

Critical of Nixon's well-publicized trips to France and England, Mrs. Ford drew applause when she said, "I think it's too soon for him. I don't think it's helpful to the (Republican) party."

There were a few gasps in the audience when a male reporter asked, "The husband-wife relationship under the circumstance of severe arthritis mastectomy, alcoholism: can you tell us how that works and how you suggest it should work?"

But Mrs. Ford fielded it easily with, "I think that's a very good question and logical. Many women feel after they've had a mastectomy that they are less desirable to their husbands.

"I think that's a barrier you have to get over. I was fortunate. My husband did not make me feel as though I was. On arthritis, I suppose if you're crippled in a wheelchair . . . However, I don't think we have to think of marriage as purely physical. Certainly a lot of marriages would fall flat on their face if it was left to the physical side of it. So there is something much deeper than that, if that's what you're referring to.

"I have heard that there is a definite, what you might refer to as sexual, withdrawal when people are on drugs. And I believe that's true with men and alcohol." The mostly female audience roared with laughter as she turned to her male questioner and said, "Isn't that true?" He hastened to say he didn't drink. Mrs. Ford shot back, "you're saved."

Mrs. Ford spoke of her continued work for the passage of the Equal Rights Amendment and arthritis, cancer and drug-abuse groups.

It sounded as if her husband was off and running for the presidency as she announced a whirlwind spring itinerary that included the Arab states, Egypt and Israel, and Japan. She hastened to say that their trip to Egypt and Israel "all depends on the peace negotiations. We would not want to distrurb anything like that."

In her prepared speech she went out of her way to say that while she didn't think "Jerry has an oblignation to be a candidate, because I think he did such a darn good job when he was in the White House, he might be confronted with the obligation." Mrs. Ford has said in the past she was reluctant for him to run but "if circumstances convinced me he should, I would support him with all love and conviction."

She stopped short of criticizing the Carter administration, saying, "as a person no longer in any government position, I feel free in my own personal life to be critical, but I do not want to voice that publicly."

And in a final response to a question about her celebrated face lift- "What is the psychological effect of feeling pretty again?"-Mrs. Ford laughed.

"I'm very happy I had it done; it feels good, it didn't hurt; I might even do it again someday. Best of all I think why I look so great is because i feel so good inside."