Here's a biography of her from www.findagrave.com:
The youngest of ten children, Marion Overend, was born a week before Halloween, October 24, 1893, to Mary Agnes “Lucy” Hudson and William Joseph Overend. Her birthplace was Peterborough, a city on the Otonabee River in Central Ontario, Canada, 78 miles northeast of Toronto. Her siblings were; William Frederick (1875), May Elizabeth (1877), Henry “Harry” (1880), Catherine Isabel “Kit” (1882), Lucy Magdalene (1884), Kenneth Vincent (1886), Mary Helena “Helen” (1888), Arthur Aldridge (1890) and Clara Helen (1892). Her mother Mary passed in 1901 at the age of 48, and her father William, followed in 1913 at the age of 62.

Marion followed her older sister May to New York and enrolled in the school of nursing offered by Mount Sinai Hospital. May graduated a few years ahead of Marion, who received her diploma on March 7, 1916, along with 50 others. She also received the Guggenheim Scholarship Award for exceptional ability.

When the United States entered the World War on April 6, 1917, obviously, doctors and nurses would be needed. With only 403 nurses in the Army Nurse Corps (ANC) when the war began, the Surgeon General called for volunteers. Women in hospitals and private duty, as well as many in training, responded. Those already staffing hospitals could join the ANC through the Army’s newly established base hospital system and through the American Red Cross. By the end of the war, 21,480 women served in the Army Nurse Corps, rendering service “beyond expectations” at a time when women were not even allowed to vote.”

Base Hospital # 3 was organized in September 1916 at the Mount Sinai Hospital, New York City, and was called to active service fourteen months later in November 1917, mobilizing and training at the armory of the First Field Hospital, National Guard, New York City. The nurses were mobilized on January 15, 1918, and the Overend sisters were among the 65 called. Departing the Port of New York on February 6 aboard the transport Lapland, they reached Glasgow, Scotland, via Halifax, Nova Scotia, nineteen days later. The nurses of # 3 were detached from the unit at Glasgow and sent by way of London to the casual depot at Blois, France, and rejoined the unit on April 18. During this travel, Marion and May had listed sister Catherine Isabel “Kit” of Peterboro, Ontario, Canada, as their next of kin. An old monastery, comprising numerous cement buildings, was turned over to Base Hospital No. 3, and in two months, these had been converted to hospital purposes, later being expanded to a hospital of 2,800-bed capacity.

On March 15, Marion was transferred to Camp Hospital # 14, located at Mars-sur-Allier, Department Nievre. On June 16, 1918, while visiting one of the surrounding flying fields, she persuaded Captain John Thorp, Jr. to take her up for a plane ride in a Nieuport Type 80 two-seat trainer with the number 951 on the side. Unfortunately, after takeoff, the plane crashed, killing Nurse Marion. Captain Thorp survived.

Before being buried in Grave # 36 at the American Cemetery, Commune of Issoudun, Indre Department, Nurse Marion Overend was rendered with Military Funeral Honors.

In October 1919, families of fallen Americans were given the option of leaving their loved ones buried in an American Cemetery in Europe with their comrades or bringing them home for reburial in a cemetery of their choice. Marion’s family chose to leave her with those she served and served with as did approximately 30% of the families facing the same decision. On September 30, 1921, she was disinterred for the final time and reburied in Plot A, Row 6, Grave 14, Saint Mihiel American Cemetery and Memorial, Thiaucourt-Regnieville, Departement de Meurthe-et-Moselle, Lorraine, France.