In view of her symptoms, your mother is likely to be suffering from Dementia. In this condition, often there is a gradual deterioration over months before the family realizes the problem. Various mental faculties such as emory for recent events, language, social judgment, sensory motor coordination, ability to plan and execute things are affected. You should take your mother to a psychiatrist who will evaluate her, order some tests to rule out other medical conditions such as hypothyroidism etc, counsel your family about the nature of illness and suggest interventions including medicines. Hope this answers your question.