1. Be sure to feed the cat enough during the daytime so she is not hungry.
2. Be sure to feed the cat an evening meal so she is filled up at night. Do this as close to bedtime as possible.
3. Feed a mix of dry food mixed with canned, along with water in the food. This should help swell the food to fill her up, more.
4. Place a dish of just a small amount of dry food right by the doorway.
5. Try a different food, in case the current food is not filling her up.
6. Do not close the bedroom door.
7. Take the cat to the vet to find out if there is a medical issue such as hyperthyroid, causing increased hunger.
8. Have all other things checked by the vet, and especially if this is a senior cat.
9. If this is a younger cat, consider a friend cat to help occupy her.
The kitty may have a health issue causing her to be more hungry, or you need to give her more food. Allow her to sleep in the same room as you, and perhaps she will feel more comfortable.