My interest in Priscilla is because I believe her daughter, Sarah Ann Bright (born 1828 in Illinois), married Thomas Gray in Switzerland County, IN.
In the 1850 census, Priscilla Bright, age 50, lived next to Thomas and Sarah. Priscilla's household included Humble, 20; Joseph, 18; Francis, 16; Elizabeth, 13; Mary J. Ryne, 7; and Joseph Gray, 18. Joseph Gray was Thomas Gray's younger brother. Other than the younger Gray and Priscilla, all were born in IL. Just based on the above, I thought maybe Priscilla was Sarah Ånn's mother.
In the 1840 census, an Ebenezer Gray was recorded in the census between Ebenezer Gray (Thomas and Joseph's father) and Joseph Gray (Ebenezer Gray's father). Thus, I think Priscilla was married to Ebenezer.
Here's where it gets interesting. I thought maybe Priscilla was widowed in 1850 but she wasn't! Ebenezer Gray in 1850 was age 44, married to 26-year-old Sarah with a one-year boy in the household. Priscilla and Ebenezer were, in my estimation, divorced.
Priscilla was in nearby Ripley County (IN) by the time of the 1860 census. Her age was weirdly off: in 1850, she was 50, born in PA; in 1860, she was 65 and born in KY. Her household included son Francis, 25; and Mary J. Ryan, 17. I didn't find your Joseph but didn't go in depth to try and find him. Ebenezer and his new wife, on the other hand, were in Marshall County (IN), which is located in the extreme north of the state. By this time, he had three children, all born in IN. Neighbors of his included two different individuals with the Bright surname: William Bright, 70, KY; and Wm. R. Bright, 33, IN. I assume they were related somehow.
For 1870, Priscilla listed her age as 73 with a VA birthplace. With her were Lucinda Brown, 6; and Surinda J. Brown, 7; with both born in IN. Ebenezer and family were still in Marshall County.
By 1880, I think Priscilla was dead and I couldn't find any of her household (including Mary J. Ryne/Ryan) anywhere. Ebenezer was apparently dead as well, as his wife Sarah was listed as head of household by that year's census. I'm trying to find out if Ebenezer left a will or any probate proceedings. I'll try the same for Priscilla, if I can find someone to do a lookup in Ripley County for me.
Hope this helps. Feel free to contact me if you need anything on Sarah's children with Thomas Gray or any of the Gray family. If you find anything more Priscilla and Joseph, please let me know.