Major Depressive Disorder (MDD) with Psychotic Features: This diagnosis is considered the most likely due to the presence of depression and magical thinking, which can be a psychotic feature. The age of the patient and the combination of symptoms such as depression and anxiety also support this diagnosis.

Anxiety Disorder: Given the patient's symptoms of anxiety, an anxiety disorder such as generalized anxiety disorder (GAD) could be a significant component of her presentation.
Dementia with Psychotic Features: In elderly patients, new-onset psychotic symptoms like magical thinking could indicate an underlying dementia process, especially if there are cognitive impairments.
Bipolar Disorder: Although less common in new onset at this age, bipolar disorder with psychotic features could present with magical thinking, especially if there's a history of manic or hypomanic episodes.

Delirium: This is a critical diagnosis not to miss, as it can present with fluctuating cognitive status, hallucinations, and delusions, including magical thinking. Delirium is a medical emergency and requires immediate attention.
Neurosyphilis: Although rare, neurosyphilis can cause psychiatric symptoms including depression, anxiety, and psychotic symptoms like magical thinking. Given its potential for serious consequences if untreated, it's a diagnosis that should not be overlooked.
Thyroid Disorders: Both hyperthyroidism and hypothyroidism can cause psychiatric symptoms, including depression, anxiety, and psychosis. These conditions are easily screened for and treated, making them important not to miss.

Schizophrenia: While schizophrenia can occur at any age, it is less common for it to first present in elderly individuals. However, it remains a possibility, especially if there are prominent psychotic symptoms like magical thinking without a clear organic cause.
Charles Bonnet Syndrome: This condition involves visual hallucinations in individuals with visual impairment and can sometimes be accompanied by other psychotic symptoms. It's a rare diagnosis but should be considered in the context of significant visual loss.
Prion Diseases: Rare neurodegenerative disorders like Creutzfeldt-Jakob disease can present with rapid cognitive decline, psychiatric symptoms, and sometimes psychotic features. Although extremely rare, they are important to consider due to their fatal prognosis and the need for prompt diagnosis.