My guess is she is the daughter of Dave. His wife died - and the children were boarded out. Then, he remarries and gets the children back.

Looked for Dave in 1880 with first wife and think this could be him - misspelled, since Taplet surname exsists in Terrebone draft registrations - but does not exsist in 1880 :

Name: Dave Toplin
Home in 1880: 4th Ward, Terrebonne, Louisiana
Age: 26
Estimated birth year: abt 1854
Birthplace: Louisiana
Relation to head-of-household: Self (Head)
Spouse's name: Julia
Father's birthplace: Louisiana
Mother's birthplace: Louisiana
Neighbors: View others on page
Occupation: Laborer
Marital Status: Married
Race: Black
Gender: Male

Ages are close - and handwriting on census - the O could be an A.

BTW here's Davids death record:

Name: David Taplett
Death Date: 27 Dec 1914
Estimated birth year: 1856
Age: 58 years

Parish: Terrebonne
Certificate Number: 14171
Volume: 9
Title: Louisiana Statewide Death Indeces 1900-1929