This is my predicament now, only mine is about a day and a half's drive away. I was already thinking about moving to his state before we met, it just so happens that I met him and it clinched it. We have been through so much together, even over the distance. Now it's just a matter of waiting until June *sigh*.
Surprisingly, I took a more leisurely approach to this relationship than with all of my past relationships. I used to be like you. I'd worry if I hadn't heard from the guy all day, whether it was through text, phone, email, IM, whatever. I'd panic. What if he stopped liking me? What if he found someone else? Holy hell, what if something happened to him??!! My man and I started out as friends. He sent me a private message after I responded on one of the threads he commented on...he liked my response and wanted to be friends. Okay, sure. I'm not one to go for a younger guy, but okay (it's only by two years). We started chatting and it ended up being HOURS of back and forth that first day. The next day, we exchanged numbers, and a few days later he asked me to to be his girlfriend. It wasn't serious at first. He was scared to even THINK about me moving down there. It took a couple of months for him to even consider it. He was confused because he felt strongly and didn't know why. It scared him. Scared me, too.
Fast forward to now, and it's going great. I talk about him a lot on here, I know...Everything makes me think of him, a lot of times the things we discuss on here are things he and I have discussed. I just love him so much and have never had such a laid back and comfortable relationship. That's exactly what it is...comfortable...content. He lets me be myself, whether I'm being silly, serious, humorous, bitchy...he loves all of it. He's the first man who has never asked me to change something about myself. We have differences of opinion and we can talk through it without yelling, without arguing, without getting mad at each other. We banter back and forth, we have debates, we challenge each other to broaden our thinking... He's my best friend. We talk every day, text when we're not working or sleeping or going about our daily lives, just talk about everything and nothing.
I would say bringing up her moving to you would depend on how long you've been together. I was in a LDR a couple of years ago and he kept saying he'd move to where I was, but he kept putting it off. I went to visit him and asked if it would be feasible for me to move there...he said it wasn't a good place for me. So, yeah. He couldn't make up his mind what he wanted. If your relationship is solid and you both have expressed love for each other, there's no reason you can't have a mature discussion about someone moving eventually. Until then, there's always vacations and weekend trips, etc.