At Airport and hour before Departure and not good enough!!

I booked a 7am flight for my daughter on my I Phone from Sydney to the Gold Coast yesterday for this morning. I emailed her the details and she arrived at the airport at 6am for the 7am flight with only carry on luggage to be told that she was too late for check in! She was told that she was suppose to be there earlier as it was a international flight and that if she paid $100 the lady could transfer her to another flight that left and arrived at the same time! When I booked from my phone it had 2 flights displayed and obviously I picked the wrong one! In the email I received it said nothing about checking in times! I have flown Jetstar a lot but will not be flying with them again unless I'm credited the $100!!! What a joke!!!