Complex sentence: There were four households none which had children under the age of 18 living with them, two were married couples living together, one had a female householder with no husband present, and one was a non-family.
Split into simpler sentences: There were four households, none of which had children under the age of 18 living with them. Two were married couples living together, one had a female householder with no husband present, and one was a non-family.