I now know that the Sarah Snyder age 12 in 1850 Henderson Co. KY census living with Rev. Wm. G. Allen is the one I have been trying to find. He married her in 1862 in Union Co. KY to George G. Hopgood.
Since he (Rev. Wm. G. Allen) married in 1844 in Henderson Co. KY and I need to find him on the 1840 census, I think that Sarah's parents died in Henderson Co. KY.
I think any siblings she might have had died with her parents. The Snyder living in Henderson & Union counties, KY for 1850 & 1860 I can't place them with her.