Joseph Smith Lanier and Nancy Jane had 10 children who lived to adulthood. Louisana was the oldest of them.
In 1870 Joseph, Nancy, and four-month-old Louisana lived in Chambers County, Alabama.[1. 1870 U.S. census, Chambers County, Alabama, population schedule, Beat #1, p. 14, dwelling 186, family 186, J. S. Lanier; digital images, Ancestry (www.ancestry.com : accessed 20 Feb 2009); citing National Archives and Records Administration microfilm M593, roll 6.] By 1880, they were in Rock Mills in Randolph County, Alabama with Louisana (listed as Lula) and four other children (Will, Emma, Jeff, and Hettie).[2. 1880 U.S. census, Randolph County, Alabama, population schedule, Rock Mills, enumeration district (ED) 114, p. 11, dwelling 72, family 82, Joseph Lanier; digital images, Ancestry (www.ancestry.com : accessed 03302009); citing National Archives and Records Administration microfilm T9, roll 30.]
The only other record I have for Lula is the 1900 census record where she is again listed in her parents' household. But I doubt she was really there.
Joseph, Nancy, and most of their children moved to Monroe County, Mississippi in 1897 or 1898. Their 1900 census record lists all 10 of their children in their household even though they weren't all living there. Lula is listed as a 31-year-old widow. [3. 1900 U.S. census, Monroe County, Mississippi, population schedule, Muldon, enumeration district (ED) 75, sheet 7A, p. 158 A, dwelling 134, family 134, Joseph Lanier; digital images, Ancestry (www.ancestry.com : accessed 03302009); citing National Archives and Records Administration microfilm T623, roll 821.]
It is certain that four of Joseph and Nancy's other children listed in that census record were living elsewhere at the time and it's possible, even likely, Lula was a fifth. While there is no proof that Lula wasn't with the family in 1900 in Mississippi, it's more likely that she married in Alabama and did not make the move to Mississippi.
A marriage record for Lula hasn't been found in Chambers or Randolph Counties, neighboring Heard and Troup County, Georgia (where a number of relatives lived), or Monroe County.
The only other information we have about Lula came from a great-niece (granddaughter of Lula's youngest sister Sallie Belle). In 2010, that niece described Lula as short and plump with white hair. She said they called her Aunt Lou and Aunt Lula but she seemed to use Lou most of the time in discussing her. Sadly, this niece could not remember a husband, surname, children, or a location where Aunt Lou lived.
Considering this niece was born in 1926 and had memories of Aunt Lou, that means she probably lived to at least the early 1930s.
If you know anything about Louisana Lanier, please email me.