Who is Irulan Corrino Atreides from Children of Dune and what is their importance?

Irulan Corrino Atreides is Paul's wife. She has been toughened by life on Arrakis, and after her husband is presumed dead, she dedicates her life to raising his children. Her refusal to age infuriates her mother-in-law, Jessica, a fellow Bene Gesserit, who has also separated in the past from the Sisterhood over love. Over the course of the novel, Irulan tries hard to convince Ghanima Atreides to marry her cousin Farad'n, even after it is shown that the Corrinos are planning Ghanima's twin brother's murder.