I believe there are some errors in your information.I have looked at the actual census for 1900 and find this:
Vermilion Co., IL, June, 1900:
George Reeder, age 47
Elizabeth, age 44
Elsie, age 16
Herman, age 12
Eve, granddaughter, age 3
In 1910 in same county:
George W. Reeder, age 57
Elizabeth Reeder, age 55
Ruby Reeder, age 4, granddaughter, b. IL, parents b. IL
This would mean Ruby was born about 1906, not 1900.If she was born in May, 1900, she would have been listed in the 1900 census since it was taken in June.
There were two other George Reeders in Vermilion Co. in 1900 and 1910, but both were older that what you say George born 1884 would have been, and both married with children.
Perhaps Elsie was not married when she had Ruby?Then there is no telling what Ruby's father's surname was, or perhaps the father was one of the married Georges?And where is Elsie in 1910?
This needs a great deal more research.