hallucinations

Grandma's hallucinations are getting worse. My dad said she got all excited around 12 noon because my sis came home with flowers at the gate. The problem is, my sister just left for australia for 2 years study and is not back! And she just claimed she saw a man lying in the garden. Her condition is getting bad quite fast and I dunno what to make of it. She's quite frightened by the hallucinations...