A brief anecdote from Grandma Nack:
When I was with the boys, I spelled their names, including their last name. Then I told them I had another name than Grandma, which was Pat. Finn looked at Henry and said, "Her last name is Grandma."
In possibly related news, alongside "Sweaty," "Nonsense," and the other firemen, Finn now deploys Fireman Jim Nack. Go figure.