Although not "official," some family trees at Ancestry.com have parents for Myron Sheldon b. 1832 VT as Hiram Granger Sheldon (1805 - 1892) and Lydia Ballou (1810 - 1891).There is a possible discrepancy, because although Hiram and Lydia had a son named Myron S. Sheldon, they lived in Mass.
There is a comment noted "Hiram Sheldon and Lydia Ballou had a son named Myron Styles Sheldon. That Myron Sheldon was not married to Laurinda Mercy Thompson Sheldon."
Unfortunately, it is sometimes to "easy" to link information together at Ancestry.com when their software compares names and dates and allows those to be a selection. Still, this may be something for Rose from the SFA to check into for you.