1 . Although the weather was bad , she went to school on time

-> Despite the bad weather , she went to school on time
 

3, Because there was a big storm, I stayed at home.

=> Because of big storm I stayed at home.

1, Although the weather was bad, she went to school on time.

=> Despite..the bad weather, she went to school on time.............................................................................

2, My mother told me to school although I was sick.

=> In spite of....my sickness, my mother told me to school.....................................................

3, Because there was a big storm, I stayed at home.

=> Because of....the big storm, I stayed at home........................................................