There was a rash of similar names at the time. In the 1880 list, Emmer, Anner, Liller, and Etter all appear. I think these are pretty clearly dialectal variants of
Emma,
Anna, etc. Ether is not on the list for 1880 as it happens, but there are 9 instances of Etha and, of course, a great many Ethels. I would feel confident in putting Ether down as a variant of Ethel/Etha and not at all related to the chemical substance.