In the 1905 Wisconsin state census of De Pere, Cecelia and Hazel are listed on the same page, but as nieces in two different families with different surnames. In the 1910 census, Hazel is still listed with that same family (Rupiper).
In 1905, William (age 55) and his son Patrick (age 22) are living with J. P. Rooney in Neenah, Wisconsin. J. P. is 38 (or 33 - hard to read - but that would make him born in 1871) and was born in Wisconsin; it says his father was born in Ireland. The best fit for J. P. is John Patrick Rooney, a cousin to William born in 1871. But he should be married and living in Avon at this time.