You would have to get a subpoena and often time police departments don't release those types of report. Did CPS get involved? If so, contact them and see if they can give you any information.
In order to get the document from a party to which you are in opposition, yes, you will need subpeona the document from either her or the police agency which took the report.
Are you represented by counsel? Are you taking depositions? There may be witnesses to testify to the occurrence.
The report itself is likely hearsay and inadmissible without the officer there to testify.