On Ancestry.com I checked the 1920 Census, and this seems to be Violet - the only one in the state!

Year: 1920; Census Place: Toledo Ward 1, Lucas, Ohio; Roll: T625_1408; Page: 3A; Enumeration District: 23; Image: 223.

Ethel HIPPLE age 31, born OH, parents OH, widow
Elma HIPPLE, age 9 dau born OH, parents OH, school
Violet HIPPLE age 5, dau born OH, parents OH, school
They were boarding on Slicking Ave in Toledo.

It looks as if Ethel remarried an Austrian and divorced him by the 1930 Census:
They are still in Toledo, Port Lawrence Twp, Slicking Ave.

Ethel MARENHOW/MARENKOM age 41, divorced, age at first marriage 20. born OH, parents OH
Lillian age 15, OH parents OH
Ethel age 15 OH OH OH
Kathryn N Marenhow?, age 9 dau, OH, father born in Austria, mother born OH

Without knowing Ethel's HIPPLE husband's first-name I could not find anything in the 1910Census. She must have married after the census was taken as there was no Ethel HIPPLE in that year.

Her husband would have died at least 1915 or later since Violet was age 5 on that census. The twin-sister Lillian wasn't shown on the 1920 Census.
And in the 1930, the older sister Elma was not in the household. I guess she could have married by then - at age 19.

Maybe someone in the Toledo area can check death records bet 1915-1920 to see if a HIPPLE died there.
Also marriage records abt 1910 since the oldest dau was age 9 in 1920 Census. Maybe there will be an Ethel who m a HIPPLE.

Hope this gives you a start!

Diana in AL