Kristen Castro remembered her baby sister, Suzanne Leong, as a devoted mother who provided around-the-clock care to her 8-year-old daughter, Aimee Ng, who was born prematurely.

Aimee was the only one in her Waimea family to survive a head-on car crash late Saturday on the Big Island that police said may have been alcohol related. She underwent surgery at The Queen's Medical Center for her injuries.

Leong, her boyfriend Brandon Ng, and their 5-year-old son, Aidon Ng, were killed in the crash. The family was on their way home from a friend's birthday party.

Rupert Tripp Jr., a guitarist with the acoustic jazz trio Kohala, was driving the other car and was injured. Tripp, of Kea'au, was also taken to Queen's.

Ng was driving a Chevrolet station wagon that crossed the center line on Highway 19 and collided with Tripp's Mercury sport utility vehicle. Police have opened a negligent homicide investigation.

Castro said yesterday that Aimee's surgery went well and she may be transferred to Kapi'olani Medical Center for Women and Children.

"Her kids were everything to her," Castro said of her sister, Suzanne, a stay-at-home mother.

Castro said Aimee required constant care as a result of her premature birth. "My sister made the choice to do that, to do whatever it took."

Castro had just moved back to the Big Island last week from Honolulu. "I've always wanted to move back," she said. "But I think there was a reason for me to come here."