Hi Jill,
I dont know the Garnetts, but some of my ancestors lived in the same area at the same time, although they seemed to have moved away c.1812.
There is no church in Sedgwick, the nearest being either Natland in the Parish of Kendal, or Crosscrake in the Parish of Heversham which are both about a mile from the village.
A lot of the land in the vicinity was owned by the Strickland family of Sizergh Hall and some of their records were referred to on A2a if you knew her father's details.
The village itself is dominated by Sedgwick Hall, owned by the Wakefield family. In 1764, John Wakefield built the first Gunpowder works in Cumbria alongside the River Kent. This industry grew over the years to support the local mining industry and provided employment for people living in the area.
The Lancaster Canal may well have been under construction through the village when she was a teenager, being completed to Kendal by 1819. This was used to transfer the gunpowder and other goods such as limestone and coal.
Hope you find this background info. useful.
Regards
Chris