Very sorry for your loss of the hen. Over the years of dealing with this issue a few times, I can give you an idea of how to prevent these problems. Digestive failure due to disease, deficient diet, intestinal parasites can all instigate crop problems. Feed the best quality ration you can that chickens find palatable. Fine bird grit or chick grit is what I mix in feed daily. A tablespoon mixed with a couple pounds of feed in a bucket works. Mix it up well before doling out in feeders. I dole out the feed in troughs and hanging feeders as needed. Give a bit of scratch every so often to exercise the gizzard. Some rolled oats on occasion is good too. It doesn't matter that grit is available in the environment. I do it anyway. Certain times of the year when grass has rapid growth, keep it cut in range areas. Long stalks and chutes are very difficult to digest. It keeps the populations of slug, snail, and bug vectors for intestinal worms down as well.
Regularly supplement water with Probios dispersible powder, and vitamins-minerals (3 days a week). Probios has superior absorption compared to others
http://www.probios.com/ . Don't toss scratch feeds among shavings. Variety in diet is beneficial, but common sense determines variety. Hard fibrous foods+limited to no grit means less digestibility and stress upon the digestive system. Worm your birds with the appropriate wormer a few times a year, or depending on the condition of droppings. Garlic, ACV, cayenne pepper, DE, are not wormers, nor will those substances prevent worms. Inspect droppings often. Don't use ACV as a regular supplement regardless of all the misinformation spread about how beneficial it is. It actually depletes calcium needed by the bird, and upsets the balance of digestive flora needed in the digestive system. I won't make that an argument.
That is a quick rundown of points I follow and do not see impacted crops anymore. One more thing. Birds which are accustomed to eating from feeders, should not run out of feed. When they do, they can gorge themselves on inappropriate objects. Too high a protein content causes digestive problems and gout. Supplementing protein during molt is beneficial, but don't do it for extended periods of time. When birds are let out of an area that contains no grass, they will quickly gorge themselves on range grasses. During the Summer, when fields are dry, I supplement with young kale. Kale is rich in Vitamin A, C,D, E, K, B6, potassium, calcium, manganese. Good luck for healthy birds and no more crop troubles.