JUPITER, Fla. -

A South Florida woman has been arrested after the 2-year-old daughter of her former domestic partner was found dead in a bathtub during the Memorial Day weekend.

Jupiter police said Kymberley Lucas, 40, was arrested on charges of murder and attempted murder.

Elliana Lucas-Jamason, 2, and her 10-year-old brother were with Lucas when, neighbors said, Lucas put the girl in the tub Sunday night. On Monday morning, she told the girl's brother to go look for Elliana.

That's when he found her dead in the tub.

Neighbors told WPBF, the ABC affiliate in West Palm Beach, that Lucas and the mother of the children had recently split up.

 Lucas was hospitalized in critical condition, but police didn't say why.

An autopsy will be performed to determine how the toddler died.