In 1927 Louis received a visit at a site called Gamble's Cave, near Lake Elmenteita, by two young ladies on a holiday, one of whom was Henrietta Wilfreda "Frida" Avern. She had done some course work in archaeology. Louis and she talked the entire night. They continued the relationship on his return to Cambridge and in 1928 they were married and set off together for Elmenteita.
Frida worked on illustrations for The Stone Age Culture of Kenya Colony. Louis was given the PhD in 1930 at age 27. His first child, a daughter, Priscilla Muthoni Leakey, was born in 1931.
In November, 1931, Louis led an expedition to Olduvai, including Reck, whom he allowed to enter the gorge first. Louis did find Acheulean tools within the first 24 hours, costing Reck ten pounds on the bet. They verified the provenance of the 1913 find, now Olduvai Man. Non-humanoid fossils and tools were extracted from the ground in large numbers. Frida delayed joining him and was less enthusiastic about him on behalf of Priscilla. She did arrive eventually, however, and Louis put her to work. Frida's site became FLK, for Frida Leakey's karongo ("gully").
With Frida's dowry money, the Leakeys bought a large brick house in Girton near Cambridge, which they named "the Close." She suffered from morning sickness most of the time and was unable to work on the illustrations for Louis' second book, Adam's Ancestors. At a dinner party given in his honor after a lecture of his at the Royal Anthropological Institute, Gertrude Caton-Thompson introduced him to her own illustrator, the twenty-year-old Mary Nicol.
Louis convinced Mary to take on the illustration of his book. A few months later companionship turned to romance. Colin Leakey was born in December, 1933, and in January, 1934, Louis asked Frida for a divorce. She would not sue for divorce until 1936.