Johann Peter Schwan had a brother called Johann Martin Schwan.
Johann Peter Schwan remarried Anna Katherian Brixius. They had 1 daughter on Jan8th 1892. Called Anna, Katherina, Sophie Schwan. She was born in Gommersheim Pfalz.
If Johann Martin called one of his sons, after his brother, or if Johann Peter Schwan had a very late baby, I don`t know. But the name of Annas father is Peter