Possible marriage records from the Illinois Statewide Marriage Index 1763-1900 for the children of George Daniels. For some of the daughters there were too many possibilities to narrow it down for certain. It seems that most of them crossed the county line and were married in Marion County, Illinois.
Index includes this information in the following order:
Grooms Name
Brides Name
Date
Vol/Page
(Licence Number) -none of these entries have information in this field
County
Verified:
DANIELS, ARTHUR T ALDERSON, ATELLA E 1900-08-14 E /78 MARION
Highly Probable:
GREEN, HENRY E DANIELS, EDITH 1894-11-18 /291 206 MARION
ADAMS, HILLARY L DANIELS, EMMA 1880-09-02 0OD/0141 MARION
JAMISON, ULYSSES GRANT DANIELS, EVA F 1889-09-26 00E/0006 MARION
MULVANEY, GEORGE W DANIELS, HARRIET A 1879-09-04 0OD/0133 MARION
**UPDATE: All of the above are CORRECT see summaries for details.
Possible:
There are a few Ida M's in the index but none in Marion or Clay County. I believe that Ida died before 1880 before the age of 10.
Multiple entries for Mary, below is the one for a Mary L. in a feasible time period but I am unfamiliar with the county. (UPDATE: Some information suggests Mary married George King, have yet to be able to verify)
BARBER, FRANK E DANIELS, MARY L 1889-12-30 H /418 ALEXANDER
Sarah A. Daniels: There are quite a few entries for Sarah but none of them are in a feasible year range in Marion County, making it difficult to determine which one is correct. (UPDATE: Some information suggests Sarah married William Buckles, have yet to be able to verify).
Lucy A. Daniels: Similar situation to Sarah, too many and not enough information to prove connection. (UPDATE: Believe she died before 1883 unmarried)