The concept of a safe person, I can understand it. A person that is always there for you. An anchor in a world that feels unreliable. Where basic human social needs are unmet. If you do not have a social network and friends. If you do not understand how to get in touch with people and what it is what makes you fail in social situations or life in general.
But it feels wildly unfair for the person who is forced to take that safe person role. If you are forced to be that person for someone who depends on you. I imagine it must be hard, when you have the obligation to sustain someone instead of having choices. To do things because both want it and not because she is hurting and needs someone. That would be suffocating for anyone.
And the dependend person isn't free but has to manipulate to get what she needs to feel safe. I think the way out should be to work towards being self sustainable and independent. No one can be that safe person for a longer time. It's a recipe for disaster over and over again. That safe person role needs to be fulfilled by oneself. Helping someone on this way is not a task for a friend or partner but a professional.
Like someone said. Distance. Maybe regular meetings as friends if you feel supportive for her. But it may be hard to keep your distance, as she guilt trips you into things again. Because it gives her the feeling of safety when she manipulates you. I don't know her, I could be wrong.
I don't think anyone should feel the obligation to be a safe person for someone. Because there is none.