The “about” section on Eleanor/Alienor, states: [quote] married, firstly, Robert de Umfreville, 9th Earl of Angus, son of Gilbert de Umfreville, 8th Earl of Angus and Elizabeth Comyn. She married, secondly, Sir Roger Mauduit before 16 August 1327. She died on 31 March 1368. [unquote]
Methinks you could appropriately place/write in your personal genealogical database her maiden name as de Lumley and most likely not be wrong. I suspect the Managed-by and the Curator omitted this in her profile.
What say you Jason Scott Wills ?
The links in her About section to The Peerage and Wiki indicate her parentage is unknown. The problem with just making corrections in our personal trees is it leaves false or questionable pathways on Geni. I came across this, for example, tracing a connection to another person. That pathway is incorrect if her parents aren't proven.
My guess would be that since she inherited the title of Countess through her mother, she retained her mother's surname rather than that of her father. I've seen this happen occasionally in feudal-era pedigrees (even sometimes with sons who inherited titles from mothers when the fathers had no titles to inherit).
(edited grammar for clarity)
Son John Mauduit looks doubtful. At any rate, Umfraville died in 1325, so Eleanor can't possibly be the great-grandmother of John de Barden, who was Mayor of York in 1378.