1880 census of Town of Wausau, Marathon Co., WI lists Carl Klug, age 54, farmer, b. Pommerania; wife Fredericka, age 36, b. Pommerania; William, son, age 7, b. Pommerania; Emma, dau., age 4, b. Wisconsin.
A cemetery inscription in Pine Grove Cem., Wausau reads "Ulrike Klug 10 Sep. 1843 -July 3,1903.These dates match the cardboard memorial card we have with the name Fredericka Klug.
I was able to find a marriage between Albertine Klug and John Wenzel in Marathon Co. on Jan. 16/1880.The 1880 census of the Town of Wausau lists John & Albertine. She is age 17, the age of Ernestine Klug in the passenger list, so apparently the same person. In 1900, Frederika Klug was living with Laura Wenzel, granddaughter.
Herman Klug is found in the 1900 census of Town of Wausau, b. Nov. 1859, age 40, b. Germany.His wife's name appears to be Minnie?, b. March 1868, age 32, WI; Anna, b. Sept. 1890, WI; Ela, b. July 1895, WI; Clara, b. June 1898, WI. In the 1910 census of the town of Wausau, Herman, age 60, is living with his son-in-law, Arthur R. Beilke.Arthur's wife is Annie (Klug), age 29.They have a daughter Gladys (unable to read age).Also in the household is Clara Klug, sister-in-law (Sister of Anna).
There is also a cemetery inscription in the Pine Grove Cem., Wausau for William Klug "1873-1912husband".It seems highly likely that this is the son of Carl & Fredericka.
I believe that Fredericka may be the second wife of Carl (possibly Charles?) Klug.There is a large gap between Julius Klug and William Klug, and Fredericka seems young to be the mother of the older children.
If you are connected to this family, please contact me.