Hello, My daugher 13 is flying alone from Quebec City to YYZ, then meeting family in YYZ to continue on to Orlando together. She has 1 hr 38 minutes scheduled connection time. Only after booking the flight did I realize she will have to go though US customs alone in YYZ.. Can someone detail the step by step she will have to go through? Also would it be quicker and better if she had no checked luggage or does it matter? Thank you so much!