"Girl, Interrupted" is a memoir, meaning it recounts the author's own experiences. Susanna Kaysen herself was the patient at McLean Hospital, and the book is a fictionalized account of her time there.
While some characters in the book are based on real people, like Susanna's friend "Daisy" who was inspired by a real person named Lisa, the character of "Lisa Rowe" is completely fictional.
Therefore, there is no "real Lisa Rowe" to speak of.