Esther Robinson, NC

I am looking for my gg grandmother, Esther Robinson b. abt 1830, NC. She was married to Essex Mathews b. 1829, NC. I found them married in Magnolia, Duplin County, NC in the 1870 Census and  I found them in Rose Hill, Duplin Couny, NC in the 1880 Census.. l am at a dead end with her family, I am looking for her parents and siblings. She could be possibly from Sampson County, since Sampson came out of Duplin in 1784. Can some one help me. I have the Mathews family information.

Thanks so very much for your help

Alice