NEW CASSEL, N.Y. (AP)  -- Three young children found dead in a bed after their mother called police claiming she killed them appeared to have been drowned, although one's throat was cut and all showed signs of possible poisoning, a homicide detective said.

1010 WINS AUDIO: Al Jones reports

Investigators are still trying to determine the precise cause of death for the children, but they are looking at several disturbing clues in the home. Police suspect that Leatrice Brewer drowned two boys and one girl _ ages 1, 5 and 6 _ and proceeded to tuck them into bed in their pajamas.

``They almost looked as though they were sleeping,'' said Lt. Michael Fleming, commander of the Nassau homicide squad. ``It almost looked like they were cuddled up together for the night.''

Fleming said foaming around the victim's mouths and noses could be a symptom of drowning or could indicate the children were poisoned with a toxic substance such as bleach. He also said the 6-year-old girl's throat was cut.

Brewer, 27, was at the Nassau University Medical Center for injuries she suffered from jumping out of their second-story apartment window, police said. Her arraignment was postponed until Tuesday on the advice of doctors, a spokesman for District Attorney Kathleen Rice said.

The children were found by police at a two-story apartment building in an impoverished neighborhood in New Cassel in Nassau County on Sunday after Brewer called 911 and said she ``killed her babies,'' Fleming said. ``She even spelled her name to the 911 operator.''

When officers went inside the apartment, they found Jewell Ward, 6, Michael Demesyeux, 5, and Innocent Demesyeux, 1, in a bed in their nightclothes, with the youngest in the middle.

It was not immediately known if Brewer, who some neighbors described as troubled, was represented by an attorney.

Brewer, who had six arrests _ two felonies and four misdemeanors _ on her record dating to 2000, was described by some as troubled, including two men who identified themselves as the children's fathers and said they had fought in vain to have the children removed from Brewer's custody.

``Whenever I tried to get my daughter, Family Court wouldn't let me,'' said Jewell's father, Ricky Ward. ``The courts wouldn't hear me out. I blame this on Leatrice Brewer and Family Court.''

Innocent Demesyeux, the father of the two boys, told reporters he had been battling Brewer for custody for more than a year.

One neighbor, Cornisha Robinson, said she saw Brewer pushing an empty stroller in the street last week and wondered where the children were.

``She neglected them,'' Robinson said. ``She used to leave them in the house all the time by themselves.''

Relatives, however, saw things differently.

``My sister's not crazy,'' Brewer's brother Robert McCord said. ``She's not ballistic. This is a shock to all of us.''

A cousin, Robin Brooks, said Brewer is ``a woman that needed help. She felt everyone was against her.''

The killings are the latest in a series of high-profile child killing cases across the country, including those of Andrea Yates, who drowned her five children in the family's Houston bathtub in 2001, and LaShaun Harris, convicted of tossing her three young sons into San Francisco Bay in 2005. Both women stood trial on murder charges but were ultimately declared legally insane _ Harris by a judge and Yates by a jury in her retrial.

In other developments, County Executive Tom Suozzi announced a review of the Social Services agency's contacts with the family to determine whether anything could have been done to prevent the tragedy. Calls to the agency were referred to Suozzi's office, which said the investigation could take several weeks.

``Obviously something went seriously wrong, and we need to determine whether part of that wrong was with the system itself,'' Suozzi said.

1010 WINS Boroughs & 'Burbs: Long Island

Photos from Nassau Police.

Top photo of Jewell Ward and Michael Demesyeux

Inset: Leatrice Brewer in 2003