When one is molting I often give mealworms / extra protein treat.Yes I have plenty of oyster shells out. I heard you can give feather fixer year round. I am thinking the feed might have something to do with it. I just switch them to this a month ago because they are molting. Thing is I only have one that is having issues. The rest are all fine.
Sounds like a few people have hens with elongated eggs though so she might be ok as this may be her norm. - as long as she is not struggling to get the egg out, one of mine had problems with that and had prolaspes, I gave calcium supplement and separated her with a friend and fed layer feed instead of grower with shell on the side, then she was fine.