Attempting to prepare her son for rule she ordered Sardaukar bashar Tyekanik as his principal instructor. She even ordered him to follow the religion of Muad'Dib, hoping that Farad'n would see the benefit of controlling his new Imperium by manipulating religious belief.
By 10216 AG she had put a spy Javid, as Alia Atreides' lover. Soon after Wensicia attempted an assassination of Leto Atreides II and Ghanima Atreides. The plot involved providing Ghanima and her brother with a royal gift of fine cloaks which a pair of servo-controlled laza tigers had been trained to recognize as prey during conditioning exercises using similar dressed human twins on Salusa Secundus. The plot, which ultimately failed, was revealed to Farad'n only afterwards and he found the use of human children to train the tigers distasteful. When word spread that Leto Atreides II had apparently been killed by the tigers and Ghanima seriously injured, the Bene Gesserit filed a formal protest against House Corrino through Sabit Rekush of the Landsraad Internal Security Commission.
When Jessica Atreides escaped to Salusa Secundus, she became Farad'n's Bene Gesserit trainer. Jessica's mode of teaching helped him to draw contrasts with his mother, whom Farad'n increasingly saw as a hindrance to his ascendancy to statesmanship, and not an advantage.
He concluded that his mother's schemes to ascend him to the imperial throne were ham-fisted, clumsy, short-sighted and distasteful. This is evidenced by his expression of anger and disgust when learning of his mother's plot to kill the Atreides twins.
Despite his mother's best efforts, Farad'n possessed none of the ambition, vindictiveness or desire for vengeance inherent in his mother. As a result, he refused to cooperate with her plans, and had her banished to an isolated area of Salusa Secundus.
Behind the Scenes
In the miniseries, Children of Dune, Wensicia was portrayed by Susan Sarandon and was seemingly reimagined as being older than Irulan (Sarandon is 27 years older than Julie Cox, who played Irulan).
When Irulan wrote "My father was 71 years old at the time and looking no older than the man in the portrait, and I was only 14 years old" in her work "In My Father's House" this created a timeline inconsistency regarding her age relative to that Wensicia. Irulan is said to be the older sister throughout the books.
Wensicia's birth year is given as 10,170, but if one cross-references Shaddam's age in the entry (71 years old), this places the event of which Irulan wrote at the year 10,189. If Irulan was indeed 14 at that year, this would place her birth year at 10,175, making her 5 years younger than Wensicia.