Just found something that might be useful.
I went back to the Tiverton census records for Elizabeth Bennett (previously Stevenson) to make sure she is recorded as being born in Loughborough and that it wasn't an error.
When I pulled up the Tiverton records for '41,'51 and '61 I found a William Towndrow living next door in '51 and '61 and living nearby in '41. He was also born in Loughborough in 1796 as was his sister Elizabeth Towndrow, born in Loughborough in 1806- the same birth year as Elizabeth (Stevenson) Bennett. He is recorded as a mechanic and his sister as his housekeeper.
In 1841 Elizabeth (Stevenson) Bennett has her mother, Elizabeth Stevenson aged 70, living with her as well as her husband's mother, Mary Worth Bennett aged 70.
So I'm wondering if the Towndrow brother and sister are related to the Stevenson family since they live next door and that perhaps the mother of the Elizabeth born in 1806 might have had the maiden name of Towndrow? Certainly an unusual name.