I have your Demarius J Vanhoy as the dau. of Isaac Vanhoy and his wife Elizabeth. Isaac is probably the Isaac who apprears with wife Elizabeth D and his family in the 1850 census, Forsyth Co, NC as follows (all born NC):
Vanhoy, Isaac....44Wheel Wright Elizabeth D....43 Anna E....14 Mary A....9 Demarias J....9 Alexander....6
I know little else of this family except that I can trace Isaac's line back several genetations.