If you go to Reporting > Custom Report.
Click New Report, then select Contacts 1 and 2, as well as Address. Run this report.
There will be a column called Address to the right of the table, which is the recorded Student home address. There will also be a column named Contact 1 address, and Contact 2 address.
You will need to export the report to Excel and manually check the Contacts Address field with the Student's Address for Contact 1 and 2, or enter a formula to check if the values in the address columns match.
You may wish to use the Family field on the student's Extended Tab, under Support Information
You can then report on this field in Reporting > Custom Report, under Display Columns and the Features Tab. Select Family Structure, and Contact 2 on the General Tab as well as Address (for you to view the student's home address).
Filter the Family column by Single Parent. You can now see which contacts do not live at the same address as the student.
Family Structure also operates as a Dynamic Field in Data Digger, so you could create a Dynamic Group for Single Parent that feeds through to the Comms area.