Answer:
1. Ask her if there's anything going on in her life that she would like to talk to you about.
2. Make sure she drinks lots of water and eats the right amount of food. Not treating your body right will mostly make you feel stressed.
3. Make sure she's staying active. Staying indoors, watching TV 24/7 with the doors closed, and over-eating is very unhealthy. Germs can also build-up and cause infections which would lead you to feel uneasy.
4. And most importantly, make sure she's not in a rocky relationship.