Some in the crowd had waited 45 minutes in the rain and considered themselves lucky, at that. The 600 tickets to Rosalynn Carter's debut appearance yesterday before the 2,200 member Woman's National Democratic Club had been snapped for four weeks earlier like the proverbial hotcakes.

"It was very important for me to see her," said a drenched but smiling Ann Robbins, struggling to get out of her rain-soaked coat. "The last time was at a campaign tea and then we had to give the tickets awat to anyone to come."

But by the time Robbins reached Carter, wearing her Inaugural turquoise wool dress as she stood between WNDC President Mary Lou Friedman and special events chairman Gerry Komer, all the things she had planned to tell the First Lady were lost in pure and simple awe. "I could only think to say 'I'm deeply moved,'" said Robbins, "and then I promptly went back (to the dining room) and spilled punch all over me."

It was that kind of a day in that strictly partisan crowd for whom superlatives would come easy, criticism difficult. Advance billing of Rosalynn Carter's maiden address to the group (many of whom could remember only too vividly one of her activist predecessors, Eleanor Roosevelt) had left little doubt that it would be important. Said the April edition of The WNDC News: "Our newest Honorary President will make what is expected to be a major statement on plans for mental health care."

Instead, "I feel like I'm campaigning again," Carter began, looking out upon a sea of faces eager for a glimpse and hint of where her programs on mental health and the elderly will be headed in the months ahead. "One thing I've had to adjust to is that my influence, no matter what I say, goes across the country," she said, paraphrasing to some ears her oft-repeated campaign statement of how as governor's wife, she began to realize how influential she could be.

Rather that be specific about her own programs, she solicited support from her audience on those of Jimmy Carter. Warning of "great and powerful forces of opposition" to his forthcoming energy policy, and "concern" for his human rights stand, she said "the point is that to succeed we need your help - it's your responsibility as mush as ours."

Later, after she had gone, taking with her the club's third annual Democratic Woman of the year award that included not just a citation but a specially designed scarf by Alexandria dress shop owner Frankie Welch, enthusiasm was polite and warm. Even so, there seemed to be an undercurrent of disappointment.

"She was very good to review for us the projects she shares with the President," said Mary Lou Friedman.

"What could she say? She couldn't say anything about policy?" asked Florence Donahue. "She was asking people to stand up for what we believe in."

"I loved her," said Sue Groth who saw nothing new in Carter's description of her own programs but thought that, too, all right because "I wouldn't have wanted her to make up something."

Another prominent Democrat, accustomed to the specifics the Club's biweekly featured luncheon speakers traditionally adhere to, suggested the occasion's "set-up" may have proved inhibiting for the First Lady.

Said a club spokesperson who had been under the impression thta Carter's speech would be newsworthy: "Apparently some decision was made later that she would hold off now and simply voice her interest."