Dr. and Mrs William H. Crocker of Washington, D.C. have announced the engagement of her daughter, Grania Nano Michelle Beauregard to George Nichols Allport of New York City. She is also the daughter of Mr. Henry G. Beauregard, law partner in the firm of Sullivan, Beauregard, Clarkson, Moss and Brown of this city. Her maternal grandmother is Mrs. P. J. Smyth of Dublin, Ireland.

The first-born in a family of six, Miss Beauregard spent her pre-college days at Georgetown Visitation Preparatory School. She is a senior in nursing at Columbia University having taken a B.S. in biology from Boston College in 1975. That year she spent the summer working in Brazil on a filming expedition for the Smithsonian Institution, and the following summer she took courses at the American College in Paris.

Mr. Allport is the only son of Mr. and Mrs. Peter W. Allport and the only grandson of Mr. and Mrs. George G. Nichols, all of Bronxville, N.Y. His paternal grandmother is Mrs. Mildred Allport of McLean, Va. He went to prep school at The Brooks School in North Andover, Mass., and took a B.A. degree in history from The George Washington University in 1976. He is an underwriter in the commercial casualty department for Chubb and Son, Inc., New York City. His father is president of the Association of National Advertisers.

Miss Beauregard and Mr. Allport are planning a late spring wedding.