Advice for each situation:
- A friend who has a splitting headache (take a painkiller): You should take a painkiller.
- Your brother who feels tired (go to sleep): You should go to sleep.
- Your sister who's got toothache (see a dentist): You should see a dentist.
- A friend who always loses his keys (keep them in your pocket): You should keep them in your pocket.
- A friend who is nervous about her exams (not worry so much): You should not worry so much.
- Your aunt whose feet hurt (take off your shoes): She should take off her shoes.
Note: For point 6, the advice is given about 'your aunt', so 'you' in the phrase 'take off your shoes' should be changed to 'she'.