Who (or what) was Sonny?

So casually mentioned...

I can tell you thanks to the 1910 census that Mary was a 22-year-old public school teacher in 1910, living with her parents. Her father was a night watchman and her mother was a seamstress. She was born in Iowa but her parents were from Switzerland-Italian. Can't trace much about the sender, Cora. No siblings or immediate neighbors had that name. Sonny (poor Sonny!) also remains a mystery.

Mary's grandson is pretty active online on his family's history. Looks like we may never find out about old Sonny. 

His response:

Thank you for the interesting postcard, apparently from shortly before my grandmother came out to Washington. Unfortunately I don't know anything about the writer, or Sonny, or even any connection to the places mentioned. My grandmother's family had immigrated to Iowa from Switzerland before moving to Almira, Washington, and my mother had contact with other members of the extended family, but all of that generation are long passed, and I have no information on their descendants.

Awww, thanks for trying, Mike! I did look to see if anyone named Sonny or Sonnie had died in MN in 1910; looks like no, if they were a person with that name. Maybe it was a pet?