You should check on the status of the loan with the lender who you applied with. The should have provided you with details on how to follow up. Otherwise, check with the school's financial aid office.
If you are denied for a PLUS loan, your students should be able to apply for additional unsubsidized Stafford loan amounts. Otherwise, they might be elgible for other financial aid. You would have to work with the school to figure out your options.