Hi,
There was a Mary Caswell baptised 22/11/1700 at Bishops Canning, Wilts, however her Father was John Caswell, and he was a yeoman. Also there is a marriage for Mary Caswell 21/5/1730 aged 28 years to a Hugh Potter aged 28 years from Cherwin, Wilts. Hugh was also a yeoman, and they were married at St Mary Devizes. Their Bondsman was Chas Chitter.
regards.