His mother believed to be Lydia Thomas from the same area / he also had the name of Llewellyn
Thomas Griffith Llewelyn Cadwallader was baptised at Tenby in 1877. Probably related to Harriet Ann Cadwallader baptised 1875 born 1874 and Florence Ann Cadwallader born 1882 baptised 1882, at a push could there be a connection with Esther Mary Cadwallader bapt 1887 at Tenby.
A Thomas is noted as the son of John & Elizabeth Cadwallader baptised at Manorbier 14 Feb 1877, this is not the Thomas baptised at Tenby
I have been doing a little research on the Cadwalladers of Pembroke & Neath Farm Rhoscrowther, so will pass this link on to someone who has far more knowledge on the family both in Tenby and Manorbier than I, in the hope they can be of assistance to you.
Rgds
Orielbenfro
ORIEL a welsh window on a surname