Schizophrenia typically develops in the late teens and early 20s. It’s not common for an individual to develop symptoms after the age of 40 but it is quite possible. It is also possible that your friend has a neurological problem.
You are correct to be concerned about your friend. It is imperative that she undergo an evaluation with a medical professional as soon as possible. Considering your distance, your ability to effectively intervene is limited. If possible, contact those who are caring for her, express your concerns and suggest that they have her medically evaluated immediately. If no one else is available to assist her, then you may want to travel to her location.
You’re obviously a caring and loving friend. She is fortunate to have someone who cares so much about her well-being but you must do what is best for your friend. Moving her into your home seems like the poorest option. She is not thinking clearly and thus is, in all likelihood, unable to make fully competent decisions about her care. She will be best cared for by medical professionals in her hometown, with the support of her immediate family. Given her symptoms and instability, it would be difficult and perhaps traumatic for her to travel the thousand miles to your home. How long will it be before her paranoia is directed at you and your family? She also might require much more care than you are able or willing to provide.
Please consider writing back to let me know how your friend is doing. I hope that she’s able to receive the help that she deserves. Please take care.