1. she didn’t need / needn’t have to take any money because her friend was going to pay. 2. we needn’t have / couldn’t have ordered so much food as nobody was hungry. 3. i don’t need to / shouldn’t wear glasses because my eyesight is still quite good. 4. you need / must be a member of the library before you can borrow books.
2. couldn't
3. don't need
4. must