want to add a second instance of product but can’t duplicate SKU

I’ve been asked to add an existing product as a variation on another, related product. The problem is I get a duplicate SKU error. Wondering if there’s a workaround.

The website sells blankets and throws. The blanket is a variable product and comes in Single, Queen, and King sizes. The throw is a simple product and comes in one size. I’d like to add the throw size as an additional variation on the blanket product but still keep the throw size as a standalone.

To get more concrete, here’s the throw: https://swansislandcompany.com/product/watercolors-throw/

Here’s the blanket: https://swansislandcompany.com/product/watercolors-blanket/

What they’re asking for is to add the throw as a size option on the blanket page. They still want the throw to be available on its own page.

Is it possible to do this without creating a new SKU?

Thanks.

The page I need help with: [log in to see the link]