According to your description she may be suffer from Alzheimer's disease,it is common in old age .
In this case homoepathy medicine can help very well and it is natural and safe treatment.
Other systems have only antidepressant and not safe treatment
I would like to suggest u pls don't leave her alone it may prove dangerous.
Maintain happy environment
Feed her on time
Always take care of her
Next Steps
u can consult with us .u can also take online prescription from us
I m also a psychologist so I can better understand the problem