Since no one has posted a followup reply to your request for information about your ancestor Fredrick Henry Aden, I decided to see what I could locate for you since Illinois is a relatively good state to do research in, although the German Adens in who settled in Illinois aren't really my area of Aden "expertise".
The uncle with whom your Adens lived is Harm Frriedrick Behrends who was born in Germany April, 1839, and died April 2, 1921 near Rantoul, Champaign, IL.He came to America in 1868, was a naturalized citizen, and appears to have moved across IL from Adams Co, to Livingston Co, to Champaign Co.He married his second wife Mina Mayer on October 31, 1881, in Livingston Co.
In 1900 three of the Aden children,Alta, Fredrick, and Ehm, are living with Harm and Mena Behrends at Rantoul in Champaign Co.By 1910, only Alta is living with the now widowed Harm.Fred lives by himself next door, and next door to Fred is Ehm, his wife Grace, and son Harm who looks to be two months old.By 1920, Fred has moved to Jackson Co, MN.
As to who are the parents of the Aden children, my best theory is based on a marriage record I located for a Henry M. Aden to a Mrs. Gretze F. Behrens which took place on February 13, 1879 in Adams Co. IL.
A check of the 1880 census does list a Henry M. Aden as living in the Northeast Twp of Adams Co.He has 3 older children Menne 15, Mary 11, and Frank 9 who would probably be from a previous marriage and then a six month old daughter name Wipke who would be from a second marriage.His wife's name is listed as Maggie.
There are a huge number of Adens living in the Golden, IL area many of whom were members of the Trinity Lutheran Church there.Heinrich M. Aden is listed as a charter member when the church was formed in 1875.There are a long list of Adens in the coinfirmation records.
If you haven't already located some of this info, I hope it will give you a helpful start.