My "in the cart" notification from the shopper is not showing up in my shop???
there are 3 items in carts on your first page.
You cannot always see it. It's not by shop, it's either you as a registered member see the "in cart" on listings or you don't. For me, I notice I see it then for a while, I don't, then see it again.
You have several items which are in someone's cart.
The 'in cart' notification is a nudge to encourage buyers to purchase - its not data for the seller. Etsy likes to vary how these things are shown so they can test how different groups of buyers react - so it's possible that different users could see different things in the same shop. After about 30 days carted items are moved to a 'saved for later' section automatically.
@MJCountryFrenchDecor: The "in people's carts" number is a sales nudge for buyers not a tool for sellers. There is no guarantee that the number is current, that every listing in someone's cart will display that message, or anything else.
I'm not seeing any in your shop page, because you have the free shipping label on all of them. I'm sure it's a test where the cart notices can also show below the free shipping, but I don't see it now. However - inside the listings - like your pediment - I see the cart notice "Rare find, already in one cart" at the top.