The Leffingwell Record88 presents two different family traditions about Mary:
1) Thomas came to New England unmarried, but having established himself, returned to England to marry Mary White, who then came back with him.
2) Thomas married a Native American woman, perhaps the sister or daughter of Uncas, chief of the Mohegans. This would explain Thomas’ exceptionally close ties with the Mohegans, which were very useful to the early settlers.
The Record says there was no proof for either story, and none seems to have emerged since the book was printed in 1897.
On the other hand, D. L. Jacobus thought she might have been a Reynolds or a Backus.83