My 1950 Singer 15-91 is My Sweet Ada, after my G'ma Drake and my Mom. My parents bought it new, with the cabinet and stool, all of which I have. Both Mom and G'ma had the middle name Adelaide, but G'pa Drake shortened that to Ada!!! He bellowed it.
My Viking 5610 is Aunt Mary, because I inherited it from her.
My 1980's White is Millie, for my Mom, who loved this machine, for some reason.
I never thought of naming them until I joined this Board!