Complex sentence: In the late 1920s, Edwards struck up a close friendship with the Bloomsbury author, David Garnett, who dubbed her his "Welsh Cinderella" and introduced her to the other members of the Bloomsbury Group, including the artist Dora Carrington.
Split into simpler sentences: In the late 1920's, Edwards struck up a close friendship with the Bloomsbury author, David Garnett. He dubbed her his' Welsh Cinderella' and introduced her to the other members of the Bloomsbury Group, including the artist Dora Carrington.