A lot of people make that argument including the YouTube video you link

In some ways that first rock and roll artist diminish her as she is so much more than that
She’s really is an N=1 artist where no one else sounds like her. Her music is a genre of her own and is a synthesis.

It’s blues, vocal jazz, gospel and rhythm and blues and guitar hero. There is no jazz artist that sounds like her. There is no gospel artist that sounds like her. There is no blues artist that sounds like her and there is no rock and roller that sounds like her either. I think she is uncategorizable with a single genre label.

Does she reach the criteria that cross the line from rhythm and blues to rock and roll. Maybe and I wouldn’t argue someone saying yes and I would probably lean towards this

However I can see counterarguments, I would say that if there was more studio recorded material where her electric guitar playing my answer would be a more definitive yes. I guess also if there was a prominent drum with march like backbeat. As her most rock and roll sounding songs is her with an acoustic guitar and a lack of prominent drums in her song means that she doesn’t completely meet the template of a rock and roll band as we know it today. I guess if there were more work with her shredding with an electric guitar with a full band ensemble she would have fit that criteria more easier. So I can see the argument of proto-rock and roll with the likes of chuck berry building on her achievement and crossing the line. She may well be the first soul artist though.

However I guess that since the definition of rock and roll has expanded so much that if her music is released today she will be considered rock music and hence I will be leaning toward her being the first rock and roll artist. However emphasising on that kind of misses the point in what makes her great because she synthesise a lot of different genres and nothing sounds like her.

There have been people questioning why only now people are recognising her. There have been celebrated black male rock and rollers and there have been celebrated female black vocalist. However I suspect it’s the female playing a masculine associated instrument of the electric guitar that has made her become overlook. It’s the crossing of cultural gender norms that made her out of place