A bit of clarification is definitely in order.Jan Emans and Sarah Jansen had seven children (the first seven you list). Sarah probably died after the last was born in 1678.About 1680 Jan married Engeltje van Salee; Cornelia was born before 1684.
Engeltje's father was Anthony van Salee. You will find some information about the remarkable van Salee family in the supporting material for a Frontline program which PBS did about "Blurred Racial Lines of Famous Families."That URL is http://www.pbs.org/wgbh/pages/frontline/shows/secret/famous/vansallees.htmlhttp://www.pbs.org/wgbh/pages/frontline/shows/secret/famous/vansallees.html.
I found an enormous repository of van Salee lineage with a simple search on "Anthony van Salee" at Ancestry.com.