I know you asked for success stories, but I don't have one personally. I'll share my story anyway. I'm a 1L, like your girlfriend. I'm a 1L just like your girlfriend, rather. Not a 1L who likes your girlfriend. I probably don't even know her. Anyway, my girlfriend came to visit me after about two weeks of my being away at law school. A couple of weeks later, I broke it all off. The stress, the new long distance, the workload, the new friends, the new cool city, all of that contributed to the decision. She started a new grad program, too, so she had all this newness, but not quite as much as I did. It was the right decision because we had only been together for about six months and, honestly, there are some very attractive women in my law school and city. That being said, look at it as a blessing. When she's in law school (even if you're not doing the long distance thing, although I take it that you are since you wrote that she "left" to law school), you'll probably be fighting a lot. If you're not fighting a lot, you'll probably be missing each other a lot. And she'll feel guilty that you're missing her and you'll both want the relationship to be how it used to be, but it just can't be. Skype sucks because you can see the person but you can't touch them. That makes it even worse than gchat for me. I know you have been together for years, which makes it hard. But, if you're a traditional-age student, you must be 20-22, so very young. You have a lot of living ahead. Pursue your dreams just like she pursued hers and the rest will fall into place. Law school is a meat market. Any chick with halfway decent looks has a Russian breadline of dudes trying to get a piece. You don't want to be stressing all about that. Have fun during your senior year with a relaxed mind. Because, really, you want her to make new friends in law school but you don't want to be questioning whether she's boffing them all. Yes, maybe if it's meant to be, you'll be back together. But if she's wanting to take a break after the first WEEK? Um, yeah...
I was married when I started law school and am still married now. As far as I know law school didn't strain the relationship at all. I didn't find law school any more stressful than most anything else in life. IMHO its probably less stressful than actually being a lawyer.