In the past, biographers and others stated that her given name was Dorothea after her aunt, or Dorothy, and that Dolly was a nickname. But her birth was registered with the New Garden Friends Meeting as Dolley, and her will of 1841 states "I, Dolly P. Madison".[2] Based on manuscript evidence and the scholarship of recent biographers, Dollie, spelled with an "i", appears to have been her given name at birth.[3] As spelling was more variable in those years, historians have settled on using "Dolley" as the spelling of her given name. On the other hand, the print press, especially newspapers, tended to spell it "Dolly". This included many of the newspapers of her day: for example, in the Hallowell (Maine) Gazette, 8 February 1815, p. 4, it refers to how the congress had allowed "Madame Dolly Madison" an allowance of $14,000 to purchase new furniture; and the New Bedford (MA) of 3 March 1837, p. 2 referred to a number of important papers from her late husband, and said that "Mrs. Dolly Madison" would be paid by the Senate for these historical manuscripts. Several magazines of that time also used the "Dolly" spelling, such as The Knickerbocker, February 1837, p. 165.[4] it should also be noted that many popular magazines of the 1860s-1890s preferred the "Dolly" spelling, and also noted that she was often called "Mistress Dolly," including in an essay from Munsey's Magazine in 1896.[5] It is also worth noting that Lucia Beverly Cutts, her grand-niece, in her "Memoirs and letters of Dolly Madison: wife of James Madison, president of the United States" (1896) uses "Dolly" consistently throughout,[6] a usage which reflects her direct personal knowledge of the name as known to Mrs. Madison herself and the members of her family.
Reading *is* Fundamental ;-)
I’ve only seen it as Dolly. Since her Will has it spelled with just the Y and the family says it’s so, then that’s as it should be. Surely, there are records with her signature but I didn’t see any in a quick search.