Hi,
I've been wading through Meyricks in Shropshire and putting them into WikiTree (free). I came across Mary Meyrick with her son Thomas Foulkes and followed this through. I did a little more than I might have done because one of my searches found this story so there's a few entries for the Foulkes.
Mary was 20 when she gave birth to Thomas so I suspect she was married previously. I did try looking in Free BMD for Marys that married a Foulkes in Shropshire. If any of the Foulkes who married a Mary died before 1849 (when Mary married George Meyrick) it would be a strong clue. It is also possible Mary had a child "out of wedlock" since I've come across this once or twice with my ancestors.
Here's the WikiTree link to Mary Meyrick - you can look at her descendants.
https://www.wikitree.com/index.php?title=Unknown-508487&public=1Alan