Came across a Dark Ages Welsh female St. Valentine!
St. Dwynwen was the beautiful, pious and virtuous daughter of the 5th century Welsh king, Brychan of Brecknock. A certain Maelon fell in love with her, and wished to marry her. Though Dwynwen returned his love, her heart was set on becoming a nun and she rejected him. She dreamt she was given a sweet drink which saved her from his attentions, but which turned the poor young man to ice. Realising that Maelon couldn't help his love for her, she prayed that he be restored to life, that all lovers should find happiness, and that she never have the desire for marriage. Dwynwen became a nun and lived on Llanddwyn Island on the western coast of Ynys Mon (Anglesey), an area accessible only at low tide.
Her well, a fresh-water spring called Ffynnon Dwynwen, became a wishing well and place of pilgrimage, particularly for lovers because of the story above. The tradition grew that the eel in the well could foretell the future for lovers - ask questions and watch which way they turn. Women would scatter breadcrumbs on the surface, then lay her handkerchief on water's surface; if the eel disturbed it, her lover would be faithful. All this led to her connection with animals, which eventually led to the tradition that her intercession could heal injured animals.
There are churches dedicated to her in Wales and Cornwall. In recent years, her feast day has become increasingly popular among the Welsh with cards being sent just as on Valentine's Day, and her well continues to be a place of pilgrimage.