Nice setup. Recently, I put a C-More on a new Mark iii Hunter, nice combination. Have couple more C-More's on on race guns: STI MatchMaster 9mm and Witness Elite Limited 9mm. Tried mounting a C-More on S&W Model 41, doesn't fit the new PC models' rails. Had a C-More on a Hammerli Xesse Sport using an optics bridge. The bridge tended to loosen. So, I have an Ultradot with 11mm dovetail rings on order for direct mounting. You might consider the Ultradot if the C-More doesn't work out for her. Both work well for me, but not all red dots work for all people.
The suggestion that she start competition right away is a good one. Over a 35+ years of competitive sailing boat racing, I learned more on the course than anywhere else. However, I also found sailing with a lot of different folks was a good learning experience.
Best of luck to her.