how does a man so much about womans fingenails
Because when women break their nails they bitch and moan about it. Hence having plenty of experience with complaints about broken nails from women using a cash register, typing, while using shovels and other outdoor tools and also softball bats and the like.
If nails break while tightly gripping a bat and hitting a ball then tightly gripping a rifle and bashing a head in is going to definitely cause problems. If her nails were not long it would not be an issue but they were long.
Blisters and abrasions caused by using an object in the manner the rifle was used is a universal concern to males and females alike unless they have calluses and the breaking of the stock cutting the hand likewise a universal concern. Gloves are the only thing which eliminate such injuries.
Gloves would not help protect her nails though. At any rate no gloves were found that Sheila could have used and why would she have used gloves if she had in fact gone into a rage as claimed?