I'm sorry I don't have any information about Marie Sibilla, but may be connected through Wihlem (William?) Baus.
I have Guilelmi Baus married to Margarethae (Margaret) Schotten in my line. Would you have any information about Wilhlem/Guilelmi/William Baus -- BMD or other? His daughter Elizabeth was a great-grandfather's wife before her untimely death.
I did not see "Sibilla" (or variations Sabilla, Sebilla, Sobilla, Subilla) in the 1984 Monroe County Heritage Book.
In the Herman Flock family history from the 1984 Monroe County Heritage Book, Herman Flock (b1797) marries Agnes Baus, d of Peter & Agnes Nelles Baus. Agnes Baus Flock did not emigrate to the U.S.; she died in Stommelin, Germany 6 Sept. 1839, according to the Flock family history.
The only other Baus mention in the 1984 Monroe County Heritage Book is that of Hermann Baus, a cousin of Anna Catharina Breitmacher, who married Johann Schreier (1823-1875) -- Johann Schreier arrived in the U.S. Oct. 1856.
Good luck to you. Have you tried writing to the Archives of the Diocese of LaCrosse for church records? I have had some success obtaining church records through the Archives.
I hope that you are able to find something about Marie.