Have you checked the 1901 census? If not this could possibly be of interest to you?

1901 census Rural district DWYRAN, Anglesey
Ecc. parish St.Peter, Newborough
RG 13 5275 p.4 fol. 47

THOMAS Richard age 41 farmer own account b.Llantrisant Ang
THOMAS Margaret 37 b.Trefdraeth "
THOMAS Jane 14 mat maker b. "
THOMAS Miriam 13 b. "
THOMAS Richard 11 b. "
THOMAS Maggie E 8 b. "
THOMAS Ellen 4 b. "