I wish you the best with your girls. Since CQ really aren’t a “breed” but more of a name, I think individual hens will vary health wise. Of my remaining four one has stopped laying and has slowed down a lot. She is my rooster’s favorite and he rarely leaves her side. The other three are very healthy and laying productively still. My F1 crosses are doing well at 2. They are just a wonderful all around hen that needs special consideration to keep them going well. I switched feed last year to All Flock and gave them separate calcium and I think that was a mistake. I had a few egg issues and lost a couple so I switched them back.
Things to look out for are lethargy, pale combs and lack of appetite. My Roo Hamilton tells me when one is really bad during the day. He is a great Roo but there is little I can do for the hens once they get going down the end lane. It can go on for weeks. I just keep them comfortable and watch out for bullying.
My best advice is to feed them a quality feed for laying hens once they start laying. Plan on something standard in your area so you never have to run out. Feed them well and take care of their crop health. And if possible breed them to a different Roo so you can enjoy their progeny too