In 1905, Wisconsin had a 2nd mid-decade census. Otto Junghans and wife Hulda lived with their two children, Otto Jr and Martha on their farm in Mequon, Wisconsin.
Also living with them was Martha's father, Ehrenfield Hahmann (though the census record didn't list the last name, leading one to believe his last name was Junghans) and a 12 year old named Lydia.
I am not sure whether Lydia was a family member since a last name wasn't used for her either. The document indicates Lydia was born in Michigan and as far as I know, no Junghans' ever lived in Michigan so I'm inclined to believe she was a relative of Hulda or possibly a boarder.