Throughout the Victorian period, thousands of orphans and other
unparented children existed on the fringes of society, where they were
at once more pathetic and more of a threat to social stability than
children in even the poorest of families.
http://www.victorianweb.org/genre/childlit/childhood4.html
Such figures often feature in
children's literature, for propagandistic or less stridently didactic
purposes. These solitary pilgrims or wayward souls were useful in the
development of individual narratives, and also contributed to the
development of the genre as a whole.