She is married to Gillis de Kerf.
Permission for the marriage has been obtained in Hontenisse on November 4, 1685.Source 1
datum: 4 nov 1685; naam bruidegom: Gillis de Kerf; weduwnaar van: Janneken van Boxelaer; naam bruid: Maria Backers; scan: 18; link naar scan: https://www.familysearch.org/ark:/61903/3:1:3QS7-89QJ-34R1?i=17&cc=2036997