NEW YORK, April 19 (Xinhua) -- A 55-year-old former nanny who stabbed two children to death was convicted of murder Wednesday with the jury rejecting her claim that she had suffered an "undiagnosed mental illness".

Yoselyn Ortega, who had worked for the victims' family as a nanny for about two years, stabbed six-year-old Lucia and two-year-old Leo to death with a kitchen knife in the bathroom of their apartment in 2012, while the children's parents were away.

The 12-member jury found Ortega's defense that she was too insane to realize what she was doing when she stabbed Lucia more than 30 times and Leo five times unbelievable.

Prosecutors maintained that Ortega, who was in a financial plight, acted out of jealous hatred of the children's mother, according to local media.

The children's father, Kevin Krim, attended the ruling in New York Supreme Court, crying when he heard the verdict. The children's mother, Marina Krim, posted photos of the children online after the verdict, writing "I love you" on them.

Ortega faces life term when she is sentenced next month. If she had been found not responsible due to mental problems, she would have been sent to a mental institution.