Chicken layed egg with no shell, twice

[free range by day]

Hi, one of my hens has layed an egg without an egg shell ( or very thin, almost like a wet paper towel shell) . This is the second day in a row she has done this. I have 11 laying hens, but this one is one of four almost 3 years old Rhode Island Reds.
( I know she’s the one because I saw her lay the first one and when she sat up to check, she started eating it)
This is the first time I’ve gotten a shell less egg from any of my hens. All 11 lay super hard shelled eggs.
Could it be that only one of 11 can have a calcium deficiency or what other problem could it be? Could it be because she’s an “ older chicken? TYIA.
Also want to add, diet and feed has not changed, they free range .

 

[Wyorp Rock]

Is she just now coming back into lay from winter break or has she been laying normal shelled eggs for the last several weeks?

It would be a good idea to look her over for lice/mites, consider getting a fecal float to see if worms may be an issue. I would also make sure her crop is emptying overnight as well, just to rule that out too.
Have you noticed any changes within the flock with the pecking order, added any new birds that may have cause some stress or anything like that?

If you don't find any parasites, she doesn't seem stressed, then giving her extra calcium for 3-5 days may be beneficial. 1 Caltrate popped into the beak once a day and let her go.

https://www.backyardchickens.com/articles/common-egg-quality-problems.65923/

 

[free range by day]

We have adopted one surviving hen from a near by neighbor due to her flock mates being taken from their coop and killed by an animal. That was in January, but she surprisingly fit right in without issues . She was the one stressed for the first couple of weeks as my hens were letting her know they were here first. There never was an egg interruption from anyone and they all get along pretty good. In fact, the adopted hen has just come back into lay after being traumatized and then put with a new flock. This particular hen that is laying shell less eggs is one of the four RIR that are the more dominate out of all of my hens.
I will check for those other things you mentioned and offer her extra calcium.

 

[McChooky]

One of my young hens laid a lash egg. I also found shell less eggs twice but wasn't sure who laid them.I haven't had any other unusual eggs since she passed.

 

[Mrs. K]

It happens and it will probably quit if you do nothing.

 

[Granny23]

I got a shell -less egg this morning. They are strange aren't they?. Not exactly sure who laid it.
I have 4 hens.
For the past 5-6 months I've been getting at least 3 eggs every day and some days 4 since they all started to lay. They are all over 6 mos old
The weather here in Southern California has been warm and beautiful except it was rainy and chilly the past 2 days. Now we are getting 1 or 2 eggs every day. Why are they not laying as much?
They have calcium available all the time, they eat lay mash crumbles and occasionally I toss vegetables to them my tortoise doesn't eat.
It's hilarious I don't have to mow my backyard grass because of these silly girls.

 

[McChooky]

The one that died laid this one.

 

[rosemarythyme]

The weather here in Southern California has been warm and beautiful except it was rainy and chilly the past 2 days. Now we are getting 1 or 2 eggs every day. Why are they not laying as much?

If it's been very gloomy lately, that could be enough to decrease laying slightly. Many birds don't lay on a consistent schedule anyhow, and sounds like your birds are young, so that's even more likely.