Widowed Lady
La Dame Veue
A nickname of Yglais, Perceval’s mother, in Perlesvaus.
The Livre d’Artus also gives her this name, but does not provide a proper name. In Livre, her husband is Pellinore, rather than Alain, and she lives in the Waste Forest.
If this is the same Widowed Lady as Sommer notes, then Lancelot and Lionel passed a night at her place.