Adair was born in Cookstown, County Tyrone, Ireland. Along with May Hezlet, Adair is the most famous Irish golfer from the turn of the 20th century. She was 17 years of age when she played in her first British Ladies Amateur in 1895. She won the prestigious event in 1900 and again in 1903. She also won four straight Irish Ladies Close Championships from 1900 to 1903.
She played several golfing exhibition matches on a 1903 tour of the United States. While there she befriended Genevieve Hecker, the two-time U.S. Women's Amateur champion. Hecker asked her to contribute a chapter on British golf for her book published in 1904 titled Golf for Women, the first book ever written exclusively for female golfers.
In 1907, Adair married Algernon Cuthell, an army Captain from West Yorkshire and gave up her career in competitive golf to raise two children. Cuthell was killed in action during World War I and after the war she remained active in women's golf circles. She was president of the Irish Ladies Golf Union for many years and held that position at the time of her death in 1961 in Portrush, County Antrim.