Diana is a young adult in The Sims 3 in Roaring Heights. She doesn't get along with her family too well, her relationship with Vince is very low. She is trying to find a future spouse for her daughters. She does not succeed with Genevra because Genevra hates children. On the other hand, she finds Harold Reed to marry Eleanor later on. She really wants grandchildren. She is very frugal.
It's known that after the events of Roaring Heights that Vince dies in World War 2 and Diana has to raise her daughter by herself. She once set up a play date for Eleanor and Laura Sanderson, but they end up become rivals later.
Her lifetime wish does get fulfilled eventually. Her daughter has a son named Lucas. It's unknown how she spent the rest of her life because she appears no where else in The Sims 3 or other Sims games.