There are very few descriptions of women’s costumes in Wales before about 1770 when tourists began to arrive in significant numbers, many of whom kept journals or make sketches. There are a few references to costumes in official documents such as the costumes given to inmates of alms houses or the very poor (by parish officials) and items of costume that people were accused of stealing.

… a country Welsh Woman, in her travelling habit; that is to say a Quoif and Croslet with a hat on their head, Waistcoat and Pett-coat, with a short Cloak hanging about her Neck, which at pleasure she doth cast over her shoulders. (illustrated)
Randle Holme (1627-1699), The Acadamy of Armory, book III, chapter V, XLVII, p. 239, folio 240, no 47