Welcome to HCM.
You have not mentioned what is worrying her.
If the cause of her worry is genuine, then that cause should be corrected.
If the cause of her worry is imaginary problem, then you need to consult a psychologist
or if the problem is severe then you must consult a psychiatrist
If her mental disturbance is due to domestic problems, then if you can resolve those problems, she may recover from her mental agony.
Wishing your mother speedy recovery.