As this is an old posting, hope you receive this info.
William G. Rose (1842 NC-1901 Dickenson Co, VA) was a Captain in Co "C" 5th Va State Line. Later in the war the Company was transferred to Co B, 7th CSA Cav Bn. This Wm. G. Rose did become a Union prisoner during the CW.
Wm. G. was indeed the son of John Mac Rose and brother of Elias Jackson Rose. If your gr-grandmother was Lovina, the dau of Elias Jackson, that married Tolbert 'Tucker' Hibbitts, Wm. G. was indeed her uncle.
Wm. G. Rose m1) Margaret Fleming, 18 Dec 1862, Wise Co, VA, the dau of R.J. "Big Jeff" and Letha 'Lettie' (Mullins) Fleming and they were the parents of 8 known children.
After Margaret's death in 1885, William G. 'Bill' Rose m2)Ruth E. Moore, 27 Sep 1888, Dickenson Co, Va. She was bc 1862 Wise Co, VA, the dau of Isaac & Emaniar (Reed) Moore. They had 5 known children.