Elsie Stillman Proxmire, daughter of Mrs. Miles McMillin of Madison, Wis. and Sen. William Proxmire (D-Wis.) of Washington and Madison, was married last Saturday evening to Dr. Alan Zwerner, son of Mr. and Mrs. David Zwerner of White Plains, N.Y. The ceremony was performed at the Colony Club in New York by Mayor Abraham Beame.

Nancy McMillin was maid of honor for her half-sister and the groom's brother, Peter Zwerner, was best man. The ushers were Theodore Proxmire, brother of the bride; Douglas Proxmire and Miles McMillin Jr., her half-brothers; and Daniel Zwerner, brother of the groom.

The bride is a granddaughter of Mrs. H. Bartow Farr of New York and the late Mr. William A. Rockefeller, and of the late Dr. and Mrs. Theodore Proxmire of Lake Forest, Ill. Her father is chairman of the Senate Banking Committee and her step-father is editor and publisher of the Madison Capital Times.

Mrs. Zwerner, an alumna of The Masters School, Dobbs Ferry, N.Y., holds a B.A. in history from Georgetown University and a B.S. in allied health sciences from George Washington University School of Medicine. She is a physician's assistant at the George Washington University Hospital where her husband is completing his final year in obstetrics and gynecology. Dr. Zwerner graduated from the State University of New York at Buffalo and the Georgetown Medical School. His father is a lawyer and assistant vice-president of the American Title Insurance Company in White Plains.

The couple plan a honeymoon in the Virgin Islands and will reside in Bethesda, Md., where Dr. Zwerner will be entering private practice in July.