Coping with a person suffering from psychosis is extremely difficult, and what seems to work in your favour on any given day may not work at all the next day.
There is conflicting advice on dealing with the delusions of another person and I would not want to even try to offer any suggestions as to how you might address that.
I hope that I would try to be consistent in my approach to your friend. Even if she has grown distant, maintain the same level of support and friendship that you have always offered to her. Eventually, she will respond and appreciate that you are still there to support her, because many others who originally purported to be her friends will not be there - many will have disappeared over the horizon at the first hint of mental illness. Such is life.
Be consistent, give her support, remember if she ignores you, belittles you, abuses you, it may be the illness talking.
Forgive her, and wait.
It is very hard to separate which behaviours are down to her illness and which are the real person.
Eventually it will become clear, but you have to be patient.
Best wishes, you clearly care about your friend, and I hope you can find your way through this difficulty.