Found Aaron and Sara Jane on CW Pension Index.
Found Sara Jane listed in Omaha City Dir. 1881.-6.-7,-8, &-98
On omahaobits.wordpress.org/ found the obit for S.J. in 1899
but Frank's birth...
Suggest you contact on http://www.omahahistory.org/
On the left, it says Email Archivist
Noticed they had some old records that might answer your question.