Mr. and Mrs. van Pelt were negligent parents
I couldn't help but find it odd that Linus' parents would allow him to spend the night alone in a pumpkin patch, shivering and asleep until the early morning hours, and leave it to Lucy to trek out to bring him home.
The parents were pretty much non-existent, even after Rerun was born. In later years, Lucy character was virtually Rerun's mother.
I know that it is a fantasy world, but I can't help but notice these things from a 21st century POV.