It is very curious that in Roger Lancelyn Green's Arthurian text, it is implied that Lynette learned magic from Nimue, while Lyonesse learned magic from Morgan le Fay (as seen in the first picture). Interestingly, Green's Lyonesse is the villain in Gareth's story after he rejected her love (because she kidnapped his dwarf) and she decides to have her revenge by ordering his assassination (via servant).
Further down the text, it is revealed that Gareth and Lynette got married. In the meantime, Lyonesse renounces doing the magic she learned from Morgan le Fay and marries Sir Gaheris years later.
Of the two existing 20th century texts that pairs Gaheris and Lyonesse together, it is fascinating that Green's text more background is added for Lyonesse in comparison to Chester Keith's 1920 Arthurian text.
References
Green, R. L. (1957). King Arthur and his Knights of the Round Table: Newly Re-Told Out of the Old Romances. Penguin Books. https://archive.org/details/bwb_KT-354-399
