The lieutenant, who asked to keep her identity private, is the first female officer to successfully complete the course since the Marine Corps opened all military occupational specialties to women in April 2016. The Washington Post gives a sense of how difficult the infantry officer course is:

The course, according to the Marines, "trains and educated newly selected infantry and ground intelligence officers in leadership, infantry skills, and character required to serve as infantry platoon commanders in the operating forces." “I am proud of this officer and those in her class who have earned the infantry officer MOS,” Marine Corps Commandant Gen. Robert Neller said in a press release Monday. The female infantry officer will now head to the 1st Marine Division at Camp Pendleton, California, for her first assignment. “The grueling 13-week course trains and educates newly selected infantry and ground intelligence officers in leadership, infantry skills, and character required to serve as infantry platoon commanders in the operating forces.”

Of the 131 Marines who began the course in July, only 88 graduated. Now a lieutenant, she is the first woman to finish the challenging course and the fourth to attempt it since the Marines opened all military occupational specialties, known as MOS, to women in April 2016. The transition for women into Marine Corps combat roles has not been smooth, as The Two-Way has reported, with some male Marines questioning whether gender integration would impact operational readiness.
The first ever female United States Marine Corps Infantry officer graduates.