Beyond joining school extracurricular activities based on her interests, she could think about joining religious, civic, volunteer or recreational organizations where she would meet other kids her age.
Being in the eighth grade is a tough year for kids under the best of situations. These are roller coaster years and you should keep those communication lines open with her as you are now. Keeping in touch with her former friends, while bittersweet, is still a good idea and let's her know everything in her old life has not died with the move. It's also important to know that being a good listener, as opposed to talking a lot or attempting to get known quickly, is an important friendship-building attribute. Everyone, including kids this age, appreciates someone who values their opinions and problems--your daughter could be one of those who fits that bill.
I wish you all a successful school year.