Whether Patrick had a wife and her name was Sheela, I don't know. But I do know that Sheela-na-gigs are ancient symbols of the goddess that was later used by Christianity to symbolize the feminine divine. They can be seen in a number of places in Ireland.
During my travels in Ireland, I saw several Sheela-na-gigs. There is a Sheela above the entrance of St. Gabnait's monastery in Ballyvourney, County Cork. In 2014, on a spiritual tour, our group prayed at her well, and visited this peaceful site. The Rock of Cashel has a Sheela on one of its outside walls. The church at Killnaboy and Brigit's monastery in Kildare also have Sheelas.
Sheela-na-gigs "represented, for women in particular, a go-to person because she represented the female. The Sheela-na-Gig is a really important part of medieval folk tradition. The figure of Sheelah was perhaps much bigger than suggested by the scant mentions we find in the old newspaper accounts. She represents a folk personification, allied to, what can be termed, the female cosmic agency, and being such, would have played a major role in people’s everyday lives. It is a pity that the day has died out. But maybe we will revive it."