Go to:

• Fees, Billing & Payments module
  
• Use the Search Fees, Billing & Payments field (top right) to lookup the Debtor (Parent) 
  
• Click 'Invoices' (left menu) 
  
• Use the check-boxes to select the invoice(s) to be generated
  
• Click the 'Actions' drop-down (top right) 
  
• Select 'Generate Invoices PDF'