The couple tried to cross the tracks after parking their car on the road last evening at a curved point without noticing the approaching Mangalore-Thiruvananthapuram Express and were hit by the train, police said.
The woman and child died en route to a hospital at Thalassery, while the husband was undergoing treatment, they said.
The couple had come to Punnole village to invite their relatives for their house warming ceremony, police said.