NEW DETAILS emerge in grim case of the alleged “KILLER NANNY”  YOSELYN ORTEGA accused of violently killing a 6 year- old girl and her 2 year-old brother!

In the case against Yoselyn Ortega, the Manhattan nanny accused of murdering 6-year-old Luica Krim and her 2-year-old brother Leo last week.

According to The NY Post , the parents of the slain children, Marina and Kevin Krim, had given the 50-year-old nanny an ultimatum to do better at her job, or they'd find someone else.

 “She was told that if she didn’t improve her work, she would be let go,” an insider said, adding those close to the situation reported that the nanny was having mental and financial issues and looked unhealthy in the month prior to the double-murder.

NYPD said Ortega told some she was planning on seeking psychological help, though it's unclear if she did. reported.

 “There was friction between her and the family," cops said, adding the nanny was also enraged at the prospects of adding an extra five hours housework to her job duties for extra payment.

“They were asking her to clean, to do housework. She was unhappy about that,” police sources told the paper, adding Ortega said the extra time would have cut into her doctor's schedule.

 “She said something like, ‘I’m paid to watch the children, not clean up and do housework,’” the source divulged.