I'm not sticking up for her, absolutely never would. But I bought 8 of those fleece throws a couple of years ago when I had a birthday BBQ.
They were brilliant, everyone who had one, whether round them or over their knees commented they did the job. I've had several bbq since and they've been washed and used many times and always appreciated.
Yes, they're not 15tog duvet but they're absolutely fine to take the chill off. Admittedly they were used in warmer months pre covid but I'd have thought that with the amount of sheds she's got her guests could either have 1 of them each or be shielded from cold with the amount of light warmth anyway