Hi, I hope someone who has a kid in a similar situation can contribute here and help you out. I am not a parent myself, but I babysat and tutored a lot of kids and I can relate to moving places during my teenage years. A girl I knew from tutoring had a hard time making friends and I tried to help her by finding out what her passion was. She seemed to enjoy arts so I suggested she tries out the school's art club. As far as I remember she met a few nice people there and she also became a bit more open.
So my suggestion would be to get your daughter outside the house and try out different things that might be fun for her..not necessarily to meet a new best friend, but for her to find enjoyment in something..and I hope the rest will follow naturally. I wish you both all the best