WB . Unit 11 - Describing peoples

1 - The lady is cooking. She looks happy, smiling and cutting vegetables.

She looks happy while she is smiling and cutting the vegetables.

If you create a list, all the items should be similar. "Smiling and cutting vegetables" are things she is doing and can go together. "looks happy" is not something she is doing.

2 - The girl is reading a book. She is wearing sun glasses and shoes.

This sentance has proper grammer. If you want it to sound more advanced you can put it together like this:

The girl who is reading a book is wearing sun glasses and shoes.

3 - The boy's watching TV. He's in the room, sitting on the couch and smiling. He's having fun.

This is good too. I would put it together like this:

He's sitting on the couch in a room while smiling and having fun watchin TV.