Maria Gunning was born at The Manor, Hemingford Grey, Huntingdonshire England in about 1732. She was baptised there on about 15th August of that year. She was a famous society beauty and indeed married the Earl of Coventry.
Her sister Elizabeth married even better - first the Duke of Hamilton, then the Duke of Argyll.
I'm currently looking into this family and in fact visited The Manor only yesterday. It is said to be the longest continuously inhabited house in England and the gardens are open to the public. You can see all about it at www.greenknowe.co.uk