Charlotte, daughter of George Grenville and his wife Elizabeth Wyndham, became the second wife of the fourth baronet in December 1771. She was a member of one of the influential political families and related to William Pitt. An heir, Watkin Williams Wynn (1772-1840), was born at Grosvenor Square on 26 October 1772. Robert Adam was commissioned to design the font

'The gift of Sir Watkin W. Wynn to the Church of Ruabon, upon the baptism of his son, December 16th, 1772'.

It is exquisite and delicate with a small marble bowl and wooden cover in the form of an urn and a wooden tripod stand, Gothic in detail. The design for the font survives in the Sir John Soane Museum. John Hinchliffe, a master of the Mason's Company, made the bowl. The wooden stand was carved in oak by Seffrin Nelson.

'1773 Feb 17
Pd Mr HincWiffe for a Marble Bason £13.13.0.
Mr Nelson, for a Carved Gothic stand £31.2.9.
For a new Font for Ruabon Church to
perpetuate the Birth of Masr. Williams Wynn.'