Using the Ancestry tree, which has Jane born in Llanllechid in 1747, there is no baptism for her there in 1747 or 1748 or 1749. This might have helped with finding Gruffydd and Lowry.
Nothing in my Welsh pedigrees either.
I checked with the NLW but nothing came up with obvious searches.
The Ancestry tree has no sources so I'm not sure how correct it is. I think Keyboard and I told you that last time. Sorry

Gadget