The dependent must be your child, stepchild, adopted child, foster child, brother or sister, or a descendant of one of these.

FORBES: Bringing Up Baby: Moms, Kids and Taxes

After reading a page on WeRelate.org about Daniel Boone, one of the most famous long hunters, Ms. Auvil says she found a wiki page link to a Kentucky state surveyor and friend of a brother of a Tennessee senator who was a friend of the man who adopted her fifth great-grandfather after his own father was murdered.

WSJ: Using Wikis and Other Forms of Group Research, Family Historians Are Making Surprising Connections

Max Shatto, born Maksim Kuzmin, and his younger brother Kristopher were adopted from an orphanage in north-west Russia last year by the Shattos, who live in Gardendale, Texas.

BBC: Max Shatto: Texas prosecutor declines charges in death

She was adopted in 1938 by her aunt, for reasons unexplained, and stayed on the Isle of Wight while her brother went to stay with their grandparents in Chichester, West Sussex.

BBC: World War II siblings reunited after 75 years apart