Hard to give specific advice without specific information.
But generally, being afraid of the unknown is natural and healthy.
One piece of advice I heard a long, long time ago was to set a goal to be superior to any role model.
A useful metaphor to use both as a directional, motivational goal AND will counterbalance any anxieties is to imagine a time in the future when you are giving advice to her, in a genuine and profound way.
As far as twin-flames, it is a useful metaphor.
But then again, everything is a metaphor, even matter itself. According to quantum and particle physics, matter is really yet another manifestation of energy.
Just be sure you're not too attached to the metaphor itself, and instead attempt to learn what the metaphor is intending for you. What growth based actions to take.
A twin flame union may be an unobtainable yet powerfully motivational goal.
To drive us to seek communion with the other halves of our very best selves.
In order to do that, you must BE your very best self.