Weird soft egg with a tail?

[swakita]

Hey guys! So I went into the coop tonight to put the chickens in for the night and found this on the floor? Its soft and squishy and has some weird tail thing on the bottom? I've had a hen who was laying soft eggs a couple days a week earlier this month but it seemed to have stopped up until last night, and then I found this today? She must have just plopped it out since I was in there not too long ago cleaning, which is strange since its about 9 PM now. They have access to calcium, and they do munch on it here and there, but 1) this one hen keeps laying soft eggs, and 2) I have never seen a "tail" on an egg before???? I'm sure its something with it being undeveloped, but I am sort of lost as to how to help her because I'm guessing this is something concerning her health? (thinking I maybe should have rinsed off the sand before taking the picture..)

 

[Wyorp Rock]

How old is the hen that is laying soft shelled eggs?

You can give her extra Calcium for 3-5 days to see if this firms up the shells. You can find Calcium Citrate+D3 at stores like Walmart, CVS, etc. Pop 1 pill into the beak once daily.

Egg with a tail...
https://www.yellowbirchhobbyfarm.com/weird-eggs-101-the-oddities-explained/