It began with suckers and ended with gingerbread clowns, and nearly all the women, including Liz Warner and Joan Mondale, wore the same dress (fashion design by the American Red Cross).

But yesterday's annual Ladies of the Senate luncheon honoring the First Lady was a social event as nearly 100 past and present Senate wives turned out for lunch in the Old Caucus Room of the Russell Senate Office Building.

Some of the members who have remained active in the club even though they no longer have husbands in the Senate were there in their blue-striped Red Cross volunteer uniforms-Mildred Morse, Abigail McCarthy, Betty Fulbright and Marian Scott among them.

First Lady Rosalynn Carter, out of uniform in black skirt and short gray jacket, was presented a Tiffany silver madonna on a chain with the inscription: "From the Ladies of the Senate."

The suckers and gingerbread clowns tied in with the luncheon's them celebrating the International Year of the Child. Tables were decorated with hand puppets, made by the club members, who turn out 500 a month for Children's Hospital.

Mildred Morse, widow of former senator Wayne Morse, has been attending the Ladies of the Senate luncheons for over three decades and remembers her first one, when Eleanor Roosevelt was First Lady.

"When I was chairman one year," she recalled yesterday, "I called the Oregon Chamber of Commerce and said I never had asked for anything before but would they send some lovely Oregon salmon. The chef did up three as if the salmon were swimming. We saved some for our husbands."

Morse said the city of Eugene, ore., has set up a park and museum on the family ranch. One display will be of cartoons when her husband was "a favorite subject." CAPTION: Picture, Elizabeth Taylor Warner