If you genuinely feel that you did everything possible then there's not a lot you can do. My only suggestion would be to go back a day or so later and look for ravens or magpies (or whatever carrion birds you have in your area) as they can sometimes lead you to a kill. I believe now that if we had gone back the next day and looked for ravens we would have found that deer. Best of luck next time and don't let your wife give up on hunting. take her to do some shooting and gain some confidence back then give her another try.