Depending on how long you have left in school, it may be advisable to wait until the permanent resident becomes a citizen before filing with CIS. The issue here is the whether or not there is an immediately available visa (based on the marriage) for the student. Prior to filing, consult with an immigration attorney.
If you filed right now, there won't be a visa available for the spouse and the adjustment will get denied. If the LPR spouse naturalizes and then files for the student spouse, there will be a visa available.