My RIR is roughly 10 months old. Today I found a soft shell egg laying on her butt feathers. She was running around fine during free range. We have had rain. Not sure if that matters. All six hens are loosing feathers but nothing crazy. I do give them oyster shells and their own cracked egg shells. The egg was torn open and rubbery. I looked in all the nest boxes and I didn't see a yolk. We have been getting good solid eggs from her. Should I be worried?