the church record of Steinefrenz(evangelical)are housed in the Archiv der Evangelischen Kirche Hessen-Nassau in Darmstadt. They charge 20 Euros for half an hour plus 10 Euros if you Transfer the money from the US. They do not accept Paypal payment.
As you have an exact date for Anna Rau it won't take more than a few minutes. So you could also ask for her parents' marriage record, provided that she was really born there. They will also ask the money if they do not find that birth record.
They do not charge the additional 10 Euros if a German would apply for that record and transfer the money from a German bank account.
If you want me to help you please sent a private message over ancestry member connect.