1. She couldn't go, because she wasn't allowed to/, because her mum didn't let her.
2. He/she must have his/her computer broken.
3. Maybe she has already eaten and she can't eat more.
4. He/she could go out with his/her parents
5. He/she must be ill.
Dziwne masz te zadania... troszke nie rozumiem sensu i czego to ma uczyć, ale niech będzie. Tylko takie coś przychodzi mi do głowy