Jonathan, I don’t want to write more detail of exactly where and how many times they hit her and how much it hurts (or doesn’t) mainly because I don’t think it advances the scene and would therefore be gratuitous. I’ve tried, now, to write enough for the reader to understand that it was horrifying, callous and caused life-threatening damage (which is all the plot requires) and to give a glimpse of the MC reacts to it and there I’ve stopped.
I’ve also remembered some partisularly usedful advice I read about writing sex – which I think applies to violence as well. Namely if it doesn’t advance the plot or reveal something about character, don’t prolong it.
Thanks, Sandra, I’ll go and have a look. I’ve read a few Sarah Hillary and enjoyed them, so will start there!