Malory seems to know nothing of her, unless she can be identified with a nameless damsel who meets Lancelot on the road and guides him to both Sir Turquine and Sir Peris de Forest Savage to stop their evil practices by exterminating them. Before parting with him, this damsel remarks it is a shame he has no lady but Guenevere, whereon he gives her an exposition on the joys and virtues of celibate bachelorhood. It is also possible she appears elsewhere in Malory, but anonymously. Indeed, she apparently has a name in only one of the manuscripts that Sommer collated. Even nameless, however, she plays a major role throughout the Vulgate Lancelot.
One day, when he had just met Amable and her brother, Carmadan, beside a fountain, Lancelot drank from the fountain and fell deathly sick – the water had been poisoned by venomous serpents in it. Amable used a combination of medicines and sweating therapy to cure him. In the process, she fell sick herself for love of him. On his recovery, he explained to her that he could not return her love because he already had a highborn lady. Amable found a way out, a way which modern society might find risible, but which accorded very well with the traditions of chivalric romance.
She told Lancelot:
All I ask is that you always and everwhere stand my friend. As for myself, I will vow never to love any other man and always remain a virgin. Thus you may love your other lady as a woman and me as a maiden, without wronging either of us.
Lancelot agreed, and Amable thus became the lady he loved best after Guenevere. Even the Queen, learning the situation, accepted Amable without the jealousy she displayed towards the Elaines.
No stay-at-home, Amable frequently appears throughout the rest of the Vulgate Lancelot, enjoying various rescues at the hands of Lancelot and others, entertaining her rescues at her castle, and so on. Amable may have been a friend or cousin of King Brandegoris’ daughter, for Lancelot once found Amable in a pavilion, and they were visited there by Brandegoris’ daughter, with her son by Sir Bors.
Source
Vulgate Lancelot | 1215-1230