On Friday at 5:22 p.m., officers with the San Jose Police Department responded to a welfare check at Emma Prusch Farm Park at 647 S. King Road.
Police said Diana Moreira, 33, was with her 1-year-old son, 11-year-old daughter and a Child Protective Services social worker for a supervised visit with the children.
The social worker took the 11-year-old daughter to the restroom, and when she came out, the mother was gone with the 1-year-old son.
While the social worker was looking for the mother and son, the daughter also went missing.
Police said they believe both children are with their mother.
Moreira is described as Hispanic, 5 feet 4 inches tall, 120 pounds, with a medium build and with brown hair and brown eyes. She was wearing a black tank top and black leggings with neon stripes.
Police have identified the victims as Priscilla and Alexander Penaloza.
Priscilla Penaloza is described as Hispanic with light brown/blond with pink tips, 4 feet 7 inches tall and 80 pounds. She was wearing a green jacket with fur on its hood and black Adidas pants.
Alexander Penaloza is described as Hispanic with black hair, 20 inches tall and about 24 pounds. He was wearing a gray puffy coat, blue jeans and black vans.
Police said the suspect might be driving a grey 2012 Mini Cooper with CA license plate 6UWL251.
Anyone with information on this parental abduction is asked to call 911 or the police department's robbery unit at (408) 277-4166.