A woman was charged Friday with killing her 18-month-old twins, named Adam and Eve, in the family home. Police said she also attempted suicide by cutting her wrists.

Stacey Smalls, 41, was charged with two counts of first-degree murder, police said.

Investigators believe one twin was strangled and the other was drowned. Authorities are awaiting autopsy results for the official causes of death.

Police also allege Smalls gave her 4-year-old daughter some type of substance to drink in an attempt to poison her. The girl is listed in stable but guarded condition at St. Christopher's Hospital for Children.

A police spokesman said Smalls, who worked as a nurse at a nursing home, then tried to kill herself by cutting her wrists. Her husband, Ronald Smalls, discovered the scene when he came home Thursday afternoon from his job as a corrections officer and called 911.

Police have not officially commented on a possible motive for the killings.

"She had something that she felt was justification but there is no justification... it's a tragedy, two young babies dead and there is no excuse for that," Police Commissioner Charles Ramsey said.

Ron Smalls told WPVI-TV on Friday that he and his wife had been having marital difficulties, but he did not elaborate.

"We've had some problems and I'd suggested therapy for both of us," he said. "She didn't think it was important."

Stacey Small changed her Facebook profile picture May 19 to a photograph of a car spray-painted along its side with the words, "Hope she was worth it." She also listed her relationship status as divorced.

A Facebook friend asked about the car image and Smalls replied that she found the photo online and "I liked her style. Friend Ronald Smalls and check out what I wrote on his page." The message may have been deleted, as Ronald Smalls' most recent post appears to be on May 13 when he wrote, "Happy MothersDay!"

Stacey Smalls' Facebook page also includes photos of her twins and 4-year-old daughter. She remained in police custody Friday and was on suicide watch, authorities said.