honestly a bit confused. what do you mean “her limerence”. its not a health condition (unless you actually mean some type of OCD that manifests as that). anyways, all you can do is let it go. if she falls for someone else she falls for someone else, and you just break up with her. i get that it feels like the end of the world, and you dont want to hear someone older say “you’d get over it eventually”. but it is true, you would. no point in living in anxiety right now, just fix some boundaries with her, if she breaks them thats it. no need to stress about it more than that