2-she had walked the dog, by the time her mum came home.
3-she hadn't taken out the rubbish, by the time her mum came home.
4-she had taken clothes to the laundry, by the time her mum came home.
5-she hadn't tidied her room, by the time her mum came home.
6-she hadn't dusted the furniture, by the time her mum came home.