What is a short summary of the story, Two's Family, in Life Ceremony?

In the story, Two's Family, when Kikue and Yoshiko turn 30, because neither of them is married, they decide to move in together. They both get artificial insemination and give birth to daughters. They raise their daughters as sisters. When they are in their seventies, Kikue is diagnosed with cancer. While visiting her in the hospital, Yoshiko wonders how their lives would have elapsed if they had never lived together.