I saw a cat bed at Walmart this morning that had catnip in it in a few places. It was perfect sized for a cat, too, but I put it back. I had already gone to the Outer Limits...
I thought I had a piece of fleece in a bin...under the bed...and maybe some stuffing that will work in a pinch.
I suggest you see where she likes to lie, first. If it’s something like under the desk, or on the table, then you’d just want to fold a blanket for her.
My parents’ old cat Sassy, the one before the present one who dislikes everyone, had towels spread on flat surfaces for morning, midday, afternoon sunbeams. Dad would say, “Sassy’s going to lie on the beach now.”