In 1931, Payne became an American citizen . On a tour through Europe in 1933, she met Russian -born astrophysicist Sergei I. Gaposchkin in Germany . She helped him get a visa to the United States and they married in March 1934, settling in the historic town of Lexington, Massachusetts , a short commute from Harvard. They had three children, Edward, Katherine, and Peter. Her daughter remembers her as "an inspired seamstress, an inventive knitter, and a voracious reader." She and her family were members of the First Unitarian Church there, where she taught Sunday school.  She was also active with the Quakers . 
Tolkowsky also developed a geometric model of the crown, on pages 80-94 of Diamond Design . To keep his model simple, Tolkowsky used a knife-edge girdle. This geometric model let him take a given pavilion angle and calculate the best crown angle and table size for that pavilion angle. Tolkowsky gave only one example: He calculated that a diamond with a pavilion angle of 40° 45' looks best with a crown angle of 34° 30', and a table size of 53%. This example includes some rounding errors. This point is starred (*) in Figure 3.