The surname is Wimmer, not Wiannce. Ann Robinett married a Jacob Wimmer-see 1860 Tazewell Co, VA census. Ann Robinett was the daughter of Daniel Robinett and Esther Waddle. Mary E. Robinett appears to the the illegitmate daughter of Ann.
Here is the family in 1850 Tazewell:
1850 Western District, Tazewell Co, VA M432 979 P233a D244 F244
Robinet, Danl 60 1790 VA Farmer
Robinet, Easter 64 1786 VA
Robinet, John R. 48 1802 VA
Robinet, Jas. P. 23 1827 VA
Robinet, Ann 32 1818 VA
Robinet, Prudence 21 1829 VA
Robinet, Mary E. 10 1840 VA
Looking at that census, Mary E. could only belong to Ann: Easter is too old and Prudence too young.
Hope this helps,