Just reading this now Pom and the title scared me too. Just a bit too far to go smack you though I know the feeling, When my 3 left for college I went through all the emotions you're going through, and it didn't get easier by the third time. But we all survived although the holidays when they came home was so special. And there were trips between although mine were 6 and 8 hours away.
Your grandaughter will feel so lost at first but it doesn't take them long to make friends. Your grandaughter has a good head on her shoulders so don't worry too much, I'm sure she'll do just great.