Sir Isaac Newton did not have any children, nor did he ever marry. He was a loner and did not interact a great deal with students, collaborators or friends.
Born in 1643, Newton spend a great deal of his 84-year life without much company. His father, an illiterate farmer, died before Newton was born. When he was 3 years old, Newton's mother remarried and left him with his grandmother for nine years. Upon the death of his stepfather, Newton's mother removed him from school to work the family farm. Lacking an interest and talent for farming, Newton soon returned to his studies and continued the education that led him to make great advances in mathematics and science.