I can't read the attachment but I think it says stepson.
The reporter on the birthcertificate is his grandfather, Abraham de Visser.
The mothers' name is not Johanna but Adriana. Abraham never had a daughter called Johanna.
Adriana de Visser married Pieter Schuitvlot on December 23 1873 in Groede.
Pieter was the son of Felix Johannis and Suzanna de Munck.
Hope this helps a bit,