A strong-willed girl, Ursilla wouldn’t marry any of the local well-born men. When she inherited her father’s estate, she married the man she’d always fancied – a lowborn barn-man. He turned out be rather unsatisfactory as a husband, and there were no children on the horizon.
A sad Ursilla went down to the seashore and let seven tears fall at spring-tide. This summoned a large male ‘selkie’, one of the seal-folk, who offered to become her lover, for at the spring tide he could take human form. After that, Ursilla indeed had a good number of children, each born with strange webbing between their fingers and toes. The midwives would cut off the webbing in order to keep Ursilla’s secret.