Mary has loads of descendants, see footnote 121 here
https://books.google.com/books?id=8JcbV309c5UC&pg=PA200
But there's only the one book line, down to Neville-59. And that section is marooned, surrounded by profiles that are badged already. It's the only Neville line not badged yet.
The FitzRandolphs of Spennithorne are also descendants of Mary Bigod, but they aren't in the book, owing to lack of unproblematic connections to any colonists.
So, I'm looking something up in Watson's Halifax and I come across a Batte story I'd missed. There was a Vicar of Halifax, Richard Marsh, whose flavour of God wasn't Puritanical enough for some tastes, so the Roundheads went round to the vicarage to tell him what would happen if he was still there next time. Or perhaps this was the next time.
Anyway, they couldn't find him, but there was a bulge in the bed, so they stabbed it. The bulge was his pregnant wife, sister of Capt John Batte, who scarpered to Virginia before they came for him. She went into labour and had the baby and died. The baby lived and probably has descendants.
(They'll be telling us all next year how the Puritans fled from persecution to religious freedom)
Anyway, what I learnt was, Rev Richard Marsh came from Berkshire, and doesn't seem to be related to the Yorkshire Marshes I was looking at. And the said Yorkshire Marshes, obscure minor gentry, descend from Mary Bigod, through the FitzRandolphs.
But the connection wasn't in place, because the key player Isabel Saville-114 had been deparented in the gedcom import years ago. So I hooked her up to her father, this very afternoon.
Little realizing that all colonial immigrants called Marsh are apparently descended from this obscure one-horse minor gentry family (with a Magna Carta and Charlemagne line), even though Marsh is a common name across most of England.
Which is where we came in, because this rigmarole explains why Arora has these lines she didn't have yesterday.