It's no wonder I'm confused!

Ruth's mother, Sophia, married Elmer when she was about 1.  They are all together on the 1920 census.

Now I'm trying to find more about Ruth.  I found a possibility on the 1930 census.  Name matches.  Approximate date of birth the same.  How Cow!  The mother's name is the same but it can't be her!  She's married to Elmer! 

Either Ruth's father is dead or her parents divorced.  I don't think they divorced and remarried.   I must not have the right Ruth on the 1930 census.  Yep.  There's Ruth on the 1930 census with her mother and step-father and she's using her step-father's name.

This is like putting a puzzle together and someone makes the pieces very close to the same with one small difference.  Pay attention or it won't all fit in the end.