It is time to introduce our newest girls to the flock and sadly, that means we need to identify & remove our non layers. Sad but their purpose is to provide eggs or meat.
We have 4 RIR that are turning 2 this spring and 3 BA that will be 1 yr this spring.
A problem with this is that hens lay in cycles once they get to a certain point. It is hard to be generic with pullets as they can do strange things but hens get in a cycle of laying during the good weather months and stopping lay in the fall/winter while they molt to replace worn out feathers. What you are probably interested in is how many eggs they lay in a year, not specifically if they are laying right now. Unless you keep good records that is hard to determine.
This link talks about putting food dye in the vent to determine who is laying which egg.
Who is laying what egg? - YouTube
Another way to determine who is laying now is to look at the vent. If it is soft, pink, and moist they are laying. It doesn't tell you how many or how often, just that they are laying. If the vent is dry and tight they are not laying.
Any individual hen may lay a lot of eggs or may not lay many at all. But on average a hen lays as many as she ever will her first laying cycle. That is from when she starts laying until her first molt. Some molt their first fall but others lay all winter and through the next year until the following fall when they have their first full molt.
After their first full molt hens typically lay really well through their second laying season. The eggs are a bit bigger and they still lay a lot. People usually want to keep them through this laying season also. Ater their second molt and going into their third laying season the average drops, maybe by 20%. This is a flock average. You can find individuals that lay much better but some will lay much worse.
We're fairly new to this, what are the typical ages?
You have seven hens now. That's about how many I try to keep in my flock. I'm not sure how many you want to keep so I'll use that number. Every year I hatch a bunch of chicks and keep 3 or 4 pullets to add to my laying flock. I keep the 3 or 4 from the previous year. At the end of that laying season after I have their eggs form their second laying season I eat the 3 or 4 oldest ones. That keep my flock young and egg production on average high.
Other people use different rotations but this one works for me.
We have one I'm pretty sure has an egg gland problem, when she lays its a softshell egg that gets crushed and makes a huge mess. We give them free choice options of crushed egg shells & oyster shell. I have caught her and given her calcium tablets for months that only slightly affects the shell quality.
I'd eat her immediately. Sometimes a hen has internal problems, call it a birth defect. Her system just doesn't work right, probably doesn't process calcium correctly. Yours are not pets, no need to keep her around when she is not earning her keep. There is a risk from this. Hens can learn to become egg eaters if they eat these broken eggs. Many hens will eat a broken egg, it is a good source of protein and other nutrients. I don't call that an egg eater. To me an egg eater is a hen that has learned to open an egg purposely to eat it. Those are pretty rare but when you get one they can cause a lot of problems. You've done what you can, it did not work. I'd cut my losses and move on.
This is a good example. During the year I sometimes have a reason to eat a hen I was not expecting to eat immediately. If I want to keep a flock of seven adults, I almost never keep just three replacements. And besides, I evaluate a pullets laying before I decide which ones to keep. I don't want to keep a faulty one like your soft shell layer. I raise extras and eat the ones I don't want to keep.
You'll soon get into your own cycle and ways to do this.
This will also be our first time processing so any tips on that are also appreciated.
You could write a book on butchering. I'll be glad to try to answer any specific questions but that is too wide a topic. I also suggest the meat bird section.
all over their run and colorful chicken feet where they stepped in it. 
