Wilhelmenia Williamson (1879-1936) aka Mena Williamson (b. April 04, 1879, Flekkefjord, Vest-Agder, Norway - d. November 24, 1936, Baudette, Minnesota, USA)
Jacob took the family to the United States in 1899.
Her siblings include: Ole M. Williamson (1881-1948) who married Doris E. Wilkens (1901-1980); Helen Marie Williamson (1887-1975) who married Edgar Pardon (1881-1973); Christian A. Williamson (1889-1939); Jacob Elias Williamson (1892-1974) who married Tilda Olson (1895-1978); Emil A. Williamson (1895-1964) who married Martha Wilkens (1902-1989); and Jenny C. Williamson (1898-1956) who returned to Norway and married Ole Johnson (1871-1961).
She also had the following half-siblings: Anne E. Villumson (1915-1963); Agnes Amanda Villumson (1919-?); Agnes Andrea Villumson (1919-?) who married Richard Larsen (1914-?); Jakob Frits Villumson (1922-1923) who died as an infant; Jakob Fridtjof Villumson (1924-?); and Petter A. Villumson.
Wilhelmenia married Bernard K. Gjelhaug (1871-1942) around 1900.
- Amelia Gjelhaug (1901-1972) who married Ludvig B. Larson (c1900-1972)
- Klarence W. Gjelhaug (1905-1980) who married Ruth Futz, and later married Clarabell A. Davis (1910-1991)
- Nora G. Gjelhaug (1907-1979who married Lionel Baril
- Agnes Gjelhaug (1909-1995) who married Frank Thorn I (1902-1983)
- Ethel Gjelhaug (1911-1912) who died as an infant
- Ralph L. Gjelhaug (1914-1993) who married Violet Nelson
- Ruth Evelyn Gjelhaug (1919-1941)
- Violet V. Gjelhaug (1920-?) who married LaVern Webber