Good morning, welcome to BYC!
You have received good response already... and I don't disagree that OS should be provided on the side. Also, be sure you aren't providing lots of treats like fruits and salad greens.. as they can unbalance the diet.
However, younger birds and older birds or any bird just entering or exiting their lay cycle can have hiccups in their reproductive tracts. Your girl is still maturing and working out the kinks so to speak. (The reason I NEVER hatch eggs from fresh layers) So calcium for egg shells is absorbed into the keel bone and then redistributed to the shell gland. It is my understanding that a hen will use up her own calcium before laying softees... so that MIGHT be the case.. but calcium is pretty important, so if she used hers up I would expect to see some health indicators which you said you don't. And yes, with changes to feed, I have had some girls protest.
It's possible the eggs are coming to fast for the shell gland to complete it's portion of the process. You call her a hybrid, does that mean mixed breed or sex link? Is she laying these in the box or randomly? Many of my girls, if they do have a softee don't even recognize it as an egg and just drop it like poo, anywhere.
Also could be genetic.
The calcium is a good place to start.. but you can keep these things in mind if it continues.
You might feed some tums or rolaids.. those are over the counter antacids, with the active ingredient being calcium (bi?) carbonate. It MIGHT help for a speedy recovery. I know people use it when their hens become egg bound because it somehow helps the muscles, sorry I don't know the process by which that happens.
Anyways, good luck! Soft eggs are one of the easier things to deal with in chicken keeping.![]()
Try providing her some crushed oyster shells. It is a great source of calcium which it takes a lot of to form the shell. I would check the label on the bags and see if there are any significant differences. If so you may want to consider changing back. I would say she just needs more calcium. It's probably not the feed if it's only effecting the one bird, but it's still a possibility. Hope this helps.