Leonie De Ruyver died without having been married. Elodie De Ruyver , too, died without having been married. De Ruyver died at the age of 18. According to the descendants of Omer De Ruyver, it is not excluded that Petrus De Ruyver had more children. Anyhow, these children would have got no descendants, otherwise they would have been known to the descendants of Omer De Ruyver.
More genealogical investigation is needed here to clarify.