Patent 3,521,902 — for a game, specifically a family game that used board and card elements.

This is a remarkable fact: two sisters from the same Davidson family, raised in the same household, both held United States patents.

The family that had produced a patented inventor in Sidney Davidson produced two patented inventors in his daughters.

The relationship between Mary Kenner and her sister Mildred is not extensively documented in the historical sources that have been written about Kenner, but the parallel achievements of the two women suggest a household in which intellectual achievement and inventive thinking were deeply embedded in the family culture.

The Davidson household was one in which the question “could this be better?” had been asked and answered, repeatedly, across generations.