Dorothy Mary Ann (Johnson) Martin

Dorothy Mary Ann Johnson was born in Forestburg, SD in October of 1923.  Here is the first record I have found for her:

This is a state cencus record from South Dakota, 1925. Here is what it tells us:

Mary Johnson was the name she went by, even at the age of 2. 
In 1925, Mary and her family lived in Onieda, SD.
She was born in 1923 in Forestburg, SD.
Her father was born in Letcher, SD
Her mother was born in Forestburg, SD
They have listed her race as white and her ancestry as Norse and either Scottish or Swedish... I'm having a hard time reading that.

I enjoy that South Dakota did a cencus but I wish it were easier to look up who went with what family.  There is no mention of siblings or parents names either.