I’m not sure if Alan deserves this – he’s not very responsive;-)
The third and last husband of Petra Johanne was a Busch, as she is listed as Petra Busch at the SSDI.
The first husband was August Ingemann.
Edit 26 Sep 2013:
Details and documentation of this marriage and family (from Danish records) has been removed due to lack of response from the starter of the thread.
Second husband must have been Conrad Petersen.
I’ll not invest more time for the moment. Sources and documentation is not included, but can be provided.