Hilary Duff Stars as Sharon Tate in New Horror Movie Trailer

Hilary Duff is saying goodbye to A Cinderella Story and hello to the Manson Murders. The 31-year old is starring as Sharon Tate in The Haunting of Sharon Tate, which revisits the horrifying murders that took her and four others lives in 1969.

"I guess you could say I live in a fairytale, looking at everything through rose-colored glasses," Duff as Tate said in an interview.

Tate was 26-years-old at the time of her murder. She was married to Roman Polanski — who was a director — and she was eight-and-a-half months pregnant with their first child — a boy.

On Aug. 8, 1969, members of the Manson cult invaded Tate's home that night while she was entertaining four friends, Jay Sebring, Abigail Folger, Wojciech Frykowski and Steven Parent, when they were all murdered. Polanski was not in their home that evening, he was in Europe working on a film.

Tate's sister, Debra, who was 16-years-old at the time of her death, is not a fan of the film — who also features Lydia Hearst, Pawel Szajda, Mean Girl's Jonathan Bennett and Ben Mellish who plays Charles Manson. In fact, in an interview with PEOPLE, she called it "tasteless" and "classless."

"It doesn't matter who it is acting in it — it's just tasteless," she said. "It's classless how everyone is rushing to release something for the 50th anniversary of this horrific event."

A scene in the film shows Tate having a "premonition" — which was Debra's take on it — that she and Sebring, who was her former boyfriend and hairstylist, would have their throats slit.

"I know for a fact she did not have a premonition — awake or in a dream — that she and Jay would have their throat cut, I checked with all of her living friends," she said. "None of her friends had any knowledge of this. Tacky, tacky, tacky."

"It's a total fabrication" she added.

Manson was serving nine life sentences at Corcoran State Prison in California where he eventually died. Debra admits she "said a prayer for his soul" the minute she found out about his passing.

The shooting of this film obviously kept Duff more than busy, and now she's suffering from a lot of "sleepless nights." The mommy of two has kept active since she gave birth to her second child, Banks. She took to Instagram to share her thoughts with fans — post-baby.

"We two months in sister. Been a lot of sleepless nights and you sure do scream a lot. But you are worth every moment my little strugglebunny," the actress posted.