Nico Slater is Wilhelmina Slater's rebellious and strong-willed daughter. She has spent many years attending various boarding schools but returned to New York City to make matters worse for her mother in the hopes of getting her attention. She is also a supporter of PETA, which infuriates the fur-loving Wilhelmina.
Nico further aggrivates her mother by trying to win over her attention by not only attracting the press to MODE but also shoplifting from Bergdorf, but both situations were handled by her mother and both escaped unscathed. This, angering Nico, prompted her to exclaim that Wilhelmina only cares for herself and the number one thing on her list should be to learn how to be a mother. Nico then says she will go to boarding school in Paris as her mother wants, but not without a fight. She apparently gets this from her father.
Nico's attitude is also a spitting image of her mother. Wilhelmina admitted she also had a rebellious streak when she was Nico's age, although Nico sees it as a joke and thinks it's just a ploy to convince her Wilhelmina really cares. Nico goes to boarding school and Willi has Marc St. James prepare her a care package. However, when the package has perfume in it, an item Nico is allergic to, Nico realizes her mother did not prepare the package. Willi, realizing her wrongs in motherhood, prepares a new package including a picture of the two and Nico's favorite gourmet jelly beans. Nico plans to return to New York for Thanksgiving. Arriving in "Four Thanksgivings and a Funeral" she finished off the feud with her mother after finding the Thanksgiving dinner her mother spent time and effort to prepare.
In the second season, Nico decided not to go to Wilhelmina and Bradford's wedding, which Marc withheld information from until Wilhelmina found out after he told Amanda in the bathroom, which leads to Wilhelmina asking Victoria Beckham to take her place as the maid of honor, a move Wilhelmina would like to forget.
In the fourth season, Nico came back, only to shock her mother when she showed up with blood all over her body. It turned out that she may have killed her boyfriend in self defense after he tried to rape her. This turn of events has Wilhelmina taking all steps to keep her from being singled out as a prime suspect. After Nico shows up, Wilhelmina helps Nico clean the blood off the boat. They throw the weapon Nico used into the ocean. The detective believes the story that Wilhelmina made up. However, unbeknownst to them, they left a drop of blood on the boat. A detective later returns with the bloody fingerprint and threatens to blackmail them. Unknown to Wilhelmina, the "Detective" is actually the supposed dead boyfriend and he and Nico have cooked up the entire scam to trick money out of Nico's mother, unaware that Wilhelmina doesn't have the money they need.
Her scheme would come undone by Marc after he witnessed Nico and Jonathan kissing and then talk about scamming Wilhelmina. When Wilhelmina confronted Nico, she claimed it was to talk the decective out of blackmailing them and Wilhelmina believed her story over Marc's. But hours later after Wilhelmina showed Nico a family necklace that she would sell off so she would give the phony detective the blackmail money, Nico, sensing a opportunity, tried to steal it. But after she opened the contents and discover that the necklace was removed, Wilhelmina confronted her red-handed, now that she knows how deceiving Nico has become as Nico claimed that Wilhelmina never wanted to bond with her by sending her off to boarding schools and was using the scheme to get back at her mother. Wilhelmina in turn threw Nico out and told her never to return, even though Nico knows that after seeing Wilhelmina eye to eye this war between mother and daughter is far from over.[[Category:Seaso