Hello My great grandmother was always said to be from Sondershausen also!! She wasn't!!! However, she was from a village in the Sondershausen diocese. The LDS Family History Center has church records from the Sondershausen diocese up until 1847. I would suggest you order these a year or two at a time and I would guess you will find the name very quickly. Once we located the parish, our family was there almost every single year as someone was being born, married or died. Good luck Roger