The name of the sister of your grandfather is Lucy. Your grandfather and his siblings are listed as the children of Salomon and Mary Smith in the 1910 US Census:
Citing this Record
"United States Census, 1910," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M299-1RS : accessed 2 August 2018), Gother Cross in household of Soloman Smith, Justice Precinct 7, Gregg, Texas, United States; citing enumeration district (ED) ED 9, sheet 7B, family 102, NARA microfilm publication T624 (Washington D.C.: National Archives and Records Administration, 1982), roll 1555; FHL microfilm 1,375,568.
According to the original document, both of their parents were born in TX. Nor Solomon or Mary were their bio. parent.
Brown was living with Solomon and Mary on 1920:
There are records at FindAGrave for your g-grandfather Lewis Andrew, for your grandfather William Jesse and for Ben and Brown as well:
Other records that may be of interest to you:
- US WW I Draft. Reg. Card of your g-grandfather Lewis Andrew:
- Dead cert. of your g-grandfather Lewis Andrew:
You grandfather was the informant.
- Your g-grandfather was living in the house of your grandfather on 1940:
- Your g-grandfather travelled to Central America on 1927:
Hope the record above helps in your search.