SAN DIEGO -- Authorities asked the public Wednesday to keep an eye out for a Point Loma Heights mother of three who went missing this week.

Rosa Lisowski, 50, has been unaccounted for since about 7:30 a.m. Monday, when she walked her son to Barnard Elementary School, according to the San Diego Police Department.

She did not have her wallet, identification or money with her at the time, officials said.

Lisowski apparently has been in a protracted child-custody dispute with her estranged husband. Neighbors told 10News that Lisowski had received threatening letters from her husband.

Police impounded the estranged husband's car on Wednesday.

Lisowski is Hispanic and is 5 feet 2 inches tall, 165 pounds, with black hair and brown eyes. She was last seen wearing dark-colored sweatpants, a black hooded jacket and leather "flip-flop" shoes, police said.

Authorities asked anyone with information on Lisowski's whereabouts to call SDPD communications at 619-531-2000.