This was Ann Niblett the daughter of William Niblett and Martha Partridge christened Jun 29, 1815 at Newent. William and Martha were married at Gloucester on Oct 18, 1810.
William, according to the 1851 census, was born in 1781. I believe he was the son of John Niblett and an unknown Elizabeth (marriage not found) and christened at Huntley on May 6, 1781.
John in turn was probably the son of James Niblett and Sarah Tomkins married at Huntley on Mar 15, 1749. John was christened there on Apr 15, 1750. It is possible that James was the son of James Niblett and Deborah Ingram and christened at Westbury on Feb 11, 1721.
The trail ends there as there are no earlier records of Nibletts in the area but I suspect that James possibly came from Painswick.