I have a good bit of information on the Lewallens in Randolph County.They originated apparently with William Lewallen (ca. 1740-1799) and Mary Dawson, in the Quaker community of Back Creek--which is near Asheboro-Greensboro.
It seems that William came to NC from the Norfolk, VA area. William had a son named Johnathan (born around 1766).I am descended from William and Mary's oldest son, Joseph (born 1763).It appears that William possibly had a brother or cousin named Johnathan as well, although my information on him is very sketchy.
William's younger sons were named Shadrach, Meshach and Thomas (all born in the 1780's). Shadrach married Sarah Hobbs.Meshach married Jane Brookshire (his sons were named Henderson, Henry, Seth and John)
The other names you mentioned I have seen in connection with William's family.I feel sure that Rebecca is a grandaughter of William (possibly great-grandaughter).