You can report on single parent families if you have recorded family information on the student's profile.
This can be recorded in the Extended tab, and under 'Support information' - there is a drop down in the Family column where you can select 'Single parent.'
You can then report on this using the custom report in Reporting > Custom report > New Report.
On the right hand side, there is the 'Display Columns' section. From here, select the 'Features' tab and tick "Family structure"
Then, click "Run Report" at the bottom of the screen