At that moment, she was not a member of the monarchy, which I despise with a passion: she was a recently widowed woman and entitled to be left alone in her grief as she buried her dead husband.
I'm not particularly "a monarchist", but I really admire the Queen. And would much prefer that she hadn't been sitting alone on that day, unless that was her real preference..
I did feel sorry for her, but my point was that the anti Boris brigade are using this as a stick to poke him with when she was not alone, but was sitting socially distanced presumably for her own health.