I was a military brat growing up, which means we moved a lot. As I got older, each move got progressively harder socially. By the time kids reach your daughter's age bracket, social cliques are pretty established, and "groups" usually aren't welcome to newcomers. It could be a long, hard, lonely adjustment time before she's let into one of those groups.
It's a great first step that you are aware and reaching out to her. These things take time, unfortunately, and she's likely to have a lot of ups and downs. I would encourage her in her interests, and the things she's good at (sports, arts, clubs, etc.) as these can be a good way to make friends. Also, you may want to consider finding a good therapist for her. DU's school of professional psychology has a sliding scale clinic, if cost is a factor. Then you can feel assured that she has at least one person she's talking to, since she's at the age when talking to mom can be tough.
Finally, I would do what you can to strengthen family bonds. One thing we were taught is that friends come and go, and life circumstances can change, but that you can always count on family. We had a family day once a week when we all went to a movie and made dinner. We would celebrate good report cards and soccer victories together; we had lot's of traditions to mark small events that are big in kids' lives.
Also, for me, especially as a teenager, I had an easier time connecting with my parents and opening up when we spent special time together outside of the normal routine. If my mom tried to get at my feelings while we were running errands in the mini-van or doing my homework, I would clam right up. My parents would each take us kids out for special outings one on one. I'm not sure how often they did this, but I still remember how my dad would take me to a donut shop at midnight, when the warm donuts would come out and going camping annually together. I remember going out for ice cream and on a weekend trip to Portland with my mom. These times made me feel loved and supported and less alone.
I hope some of these ideas work. Good luck!