This convent is mentioned in 837 when Benedictines from Fulda brought relics to the community from Rome. The nuns met the Benedictines, carrying a cross and candles, and led them into their church. The account records that a sick maid of the Abbess Mathilde was cured after venerating the relics (Link, 574).
Abbess Mathilde
Perhaps S. Afra of Würzburg, which is later recorded as being tithed for the building expenses of the parish church.
The convent was likely a dependency of Fulda.
The convent supposedly stood next to the present parish church.
The convent reportedly received relics from Rome and became a pilgrimage site in the Middle Ages (Link, 574).
Further research necessary
Little information on this community exists. Link also speculates that mention of Zellingen may refer to the convent of Karlsburg