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 have identified the victims as Priscilla and Alexander Penaloza.
Moreira was found in the Colorado Springs area and was taken into custody without incident. Both children were found safe and unharmed.