My partner is related to Sturminster Newton Inkpens and we have done some research on them but she is not directly decended from Benjamin Inkpen as far as we can tell. My records show that Benjamin Inkpen married Betty Loader on 6th August 1770 and probably had at least two children Rosanna c 17-04-1776 Sturminster Newton, Dorset and maybe Morgan c 31-01-1778 Sturminster Newton, Dorset?
with regard to the Rosanna marriage I have two options: Elisha Rose as you say or Rosanna married William YOUNG on 12-May-1796 Sturminster Newton, Dorset
In my records I also have another Rosanna born abt 1764 to parents Benjamin and Susannah and christened on 17-Feb-1764 in Sturminster Newton. I have this Rosanna as an option to marry Elisha Rose as well.