That's an excellent question. Like others who've replied before me, it makes me realise how little I've considered it up to now.
Emmy Lou Harris acquits herself pretty well (imo), for example in her concerts with Mark Knopfler, who sets a very high standard of guitar playing (again, imo).
I also love to watch Suzi Quatro showing us why chicks belong upfront in rock.
But in both cases, their overall performing and visual appeal (to my eye) may be overshadowing their guitar playing skills...