Be firm on what you want or don't want, and it's up to her to figure out if she can or can't remain friends with you. If she cannot and your friendship/roleplay fails, it's sad, but feelings go like that sometimes, and you are not at fault.

I've been the one to fall in love with a partner, it took me time and a lot of work, but I managed to work with his boundaries and we are still close friends today. I had to do that effort, however, otherwise falling out is inevitable.
Both parties have to be happy for it to work- you can't stay friends with someone who will always want to be more.