I was sure that someone on this board would know the answer to this question. I guess I'll just ask Miss Barrett at the fest. Thank you anyway, Elmont....
Elmont,
According to her bio on the IMDb, which was written by Craig Hamrick who knows her personally, produced her cabaret act at the '97 Fest etc..., Nancy has a sister named Martha and there's no indication that Martha is an actress. If Leslie Barrett was her sister, Craig would have mentioned it in the bio. So, it's just a coincidence that they have the same last name. They are not related.