NEW YORK (CBSNewYork) — Jury deliberations began Tuesday in the trial of a former nanny accused in the deaths of two young children in her care.

Closing arguments were made Monday in the trial of Yoselyn Ortega, who is accused in the fatal stabbings of 6-year-old Lulu Krim and her 2-year-old brother Leo inside their family’s Upper West Side apartment back in 2012.

CBS2’s Hazel Sanchez spoke with alternate jurors about the emotional impact of the testimony. 31-year-old Chloe Beck and 27-year-old Brittany Yee say they’ve found friendship through the horrific tragedy.

“It’s hard to have sat through and seen everything we’ve seen,” Beck said. “Things we can’t unsee.”

They sat next to each other for six weeks covering the trial, where prosecutors allege the murders were planned and said Ortega knew the consequences of her alleged actions.

“Every stab, every slash, each one had a purpose. And that purpose was to end the lives of those children,” said Assistant District Attorney Stuart Silberg.

Prosecutors claim Ortega acted out of anger against the Krims, particularly the children’s mother, Marina Krim, for allegedly over working her.

Beck got emotional when recalling the testimony.

“I don’t think I’ll ever be the same,” she said. “I remember those first few weeks I would leave and go cry in a bathroom.”

Beck and Yee are two of six alternate jurors dismissed while the remaining 12 decide if Ortega acted intentionally. Defense attorneys argued the 55-year-old suffers from severe psychosis and depression and heard voices telling her to kill the kids.

“The reason for the defendant’s actions lay within her delusional mind. The lack of the defendant’s apparent motive is the hallmark of her mental illness,” said Ortega’s attorney Valerie Van Leer-Greenberg.

Video presented in court showing Ortega denying she ever heard voices left Beck and Yee with opposing impressions.

“I think she had the capacity to understand what she’s doing,” Yee said, while Beck said she understood where the defense was coming from.

“Seeing her not really answer the questions, or like really off-topic kind of speaks to the defense’s argument that she’s not reliable,” Beck said.

Beck adds she’s traumatized from the trial, and needs therapy after all she saw and heard from her jury seat. She and Yee say they will never let go of the heartache they feel for Lulu, Leo, and their devastated family.

Ortega faces life in prison in convicted.