Sarah Blanch and Middle Names

I am a middle namer and so are many of the other people in my family.  Nonetheless, I sometimes forget to take that into account when hunting for relatives, particularly since middle namers will sometimes appear in records by the name they use and sometimes by their first name.   This was brought home recently as I was going through some Crawford county deeds.  In one instance, property was sold to Martha Hatcher and Blanch Perry, daughters of Mark Perry.  I had Mark with two daughters but they were Martha and Sarah (from the 1880 census).  Other records with the land had Blanch as S. Blanch Perry, which of course started me looking at Mark's daughter Sarah.  Taking the leap that Sarah Perry, on the census as Mark's daughter, and the Blanch/S. Blanch Perry in this record were the same, I started looking at records for Blanch.  A few years after the land record, Blanch Perry married Ezekiel Atwater.  Looking further in the census, in 1900 Ezekiel and Blanch Atwater had a son Perry.  In 1910, the parents in the family are Ezekiel and Sally Atwater (Sally of course being Sarah), and her tombstone from 1918 has Blanch P. Atwater.  In this case, the use of the middle name makes good sense, since her mother was also Sarah and this would have served to differentiate them.