When a person with schizophrenia says that people are constantly talking about her, everything is somehow related to her, people are plotting against her, and she is extremely powerful, what she is describing are forms of:

delusions.

Explanation:

Schizophrenia -

It is a type of mental disorder, where the people interprets the reality in a very unusual manner, is referred to as schizophrenia.

Proper treatment require a very lengthy treatment procedure.

The disorder can be due to hallucinations, delusions.

The person suffering from this disorder faces a lot of difficulty in the day to day activities.

Hence, from the scenario of the question,

The correct answer is delusions.