Reviewing all the sources, I found nothing at all that would serve to connect Hawise de Meschins to John Maltravers. So, imho he married "Hawise Unknown".
If I comprehend it correctly, she acquired her identity as Hawise Meschins on July 19, 2014.
Then on March 17, 2017 she was connected to this profile (John Maltravers) as his wife.
Both operations were performed by Geni Curators. On what authority, who knows (sources for supporting documentation not present on either profile). Hawise was added to the Tree on June 8, 2007 by "Skip" Bremer, and has since endured more than a hundred modifications to the profile, mainly by Curators and some mysterious entity known as "Geni".
Our Hawise also has a critical inconsistency regarding her age at the time of her alleged Bostick children.
https://www.geni.com/inconsistencies/for_profile/6000000001745009000
The sourcing for
Was from here
http://homepages.rootsweb.com/~cousin/html/p398.htm#i23438
Obviously the tree on Geni doesn’t conform.
Too ridiculous. Hugh de Kevelioc's 4 legitimate daughters became massive heiresses when their brother Randolph died without issue. They married into earldoms.
Hawise de Meschines, Countess of Lincoln had only one child, her daughter and sole heiress Margaret.
Attempt at Maltravers pedigree in very old journal (1836)
https://archive.org/stream/collectaneatopog03londuoft#page/78/