I guess I have a hard time with this because I would always prefer having a weak far-away friendship than to cut ties and burn bridges. Even if it's always me contacting them I would rather have the line of communication open in the end so that way if our paths were to cross again we can connect like old times. Perhaps I let go of people easier hmm. For example, even though I used to hang out with this one girl all the time in high school, I barely hear a peep out of her in college. She is just so busy and doesn't chat unless you start the conversation and even then it doesn't guarantee a response. But just the other day she asked for my address and is planning on sending me a present. So really people can surprise you from time to time because they really do value you even when they are busy.

The only way she'll understand that you aren't trying to manipulate her is to explain yourself well enough. Maybe write a few rough drafts to get started and see if any of them sound right to you. A true friend will understand what you're trying to say. Also try to see it from her point of view. Recently she's been very busy trying to fit in into a new environment and making lots of friends. She probably doesn't think of her friends from home as much and even if she does it's probably in passing. If she was really close to you, she'd probably be upset over why you ended it and either think you're a jerk or respect your wishes and leave it me. In my head, if someone didn't want to be my friend anymore and cut me off that is their decision and I would accept it and move onward since friendship is a two way street. And unless you've done this sort of thing to her before (or even if you did it before, depending on your wording), she probably assumed you were serious and is letting you go.

For me though, the most important part is to not leave that "what if" hanging. I would rather take the chance then wonder about it for the rest of my life. Will you be okay not contacting her and not being her friend later in life? That's something you have to answer.

Best of luck!