There is a tree on Ancestry.com named Keatsdad that has lots of info on Michael Yanker. Also try a public member tree search on Ancestry to see if others are researching your same line. Francisca may have changed her name to Fannie. There was a Fannie Yanker who married a J B Burns April 20, 1893. It's a coincidence that Michael Yanker married Amelia Franzel April 22, 1893. There was also a James A Yanker (Born 1876) married a Annie L Weaver in Ouachita, Arkansas March 6, 1901. These were the only marriages.
Here are the 2 death records
Lizzie Yanker: Died March 31, 1915
Amelia Yanker: Died January 19, 1939
There are also photos of the Yanker graves on this link