Broken egg in hen

On Saturday afternoon I noticed one hen, the best layer, was sat in the nest box for a long time. When I went to investigate I saw that there was eggy yello in the nest box and on her bottom and she was VERY lethargic. We brought her in and put her in a bowl of warm water which she seemed to enjoy. While I was on the phone to the vet. (who was not much help) she managed to get more out. We kept her in the airing cobarn overnight and kept a close eye on her Sunday. She was drinking well and was hungry and we managed to get her to eat some foot. She refused to eat a boiled egg though. Yesterday I took her to the vet. who examined her and could not feel anything left in her, not even another egg on the way. She gave her an injection of a muscle thing that would make her get rid of anything that was left and some antibiotic. I gave her some mealworms and layers pellets soaked in water and she wolfed it down. She seems quite perky this morning as we put her out in a seperate run close to the others.
Does anyone have any suggestions as to what else we can do to help her?
Do you think that she has had a narrow escape and that she is now out of the woods?
I'm back in work today and hope that she is good when I get home tonight!

Perhaps cut down on the extra protein - the boiled egg and mealworms - as these tend to increase egg size which can make laying more difficult.

She has perked up a lot over the weekend. Fingers crossed, she's on the mend.