She was enumerated in the 1900 U S Census as a daughter in the household of Jackson Brewer (wife Mary) in Lesterville, Reynolds County, Missouri. See familysearch.org record for 1900 census. Gives her birth as August 1880, not May 1879 as stated in FaG. Her name appears as Jannie. She is not listed in the Jackson Brewer household in the 1880 census for the family, then in Union, Iron County, Missouri. The census was taken 9 June 1880, and the youngest child was Lilly, then 10 months old. This may indicate that the 1900 census birth for Jannie in August 1880 is more accurate than the Find A Grave date.
The censuses gives names of other siblings of Jannie, which will help to confirm this is the "right" Anna Jane.
Unconfirmed: ancestry.com gives parents' full names of Andrew Jackson Brewer and Mary Angelina Johnson.
P.S. Unless they moved right after the census, it is likely she was born in Iron County, not Pulaski.