Based on your family having overseas friends, I'm assuming you are military. Growing up military and moving around so much only makes me wish Myspace or FaceBook had been around when I was younger. I have actually been reunited with two friends from middle school on Myspace and it's nice to be able to catch up with them and see how their lives have progressed. That being said, I think this can be a great tool in helping your daughter adjust to being in a new place and having to make new friends. The middle school years are hard enough without having to move and make new friends on top of hormones, growth spurts and having to be responsible!
I have a 12 yr old son and he has a Myspace page. So do my husband and I. We have set all of his security settings pretty high so his friends have to enter his last name or e-mail address to send him a request and we know his password. Also, because we're his 'friends' on Myspace, we see all the bulletins and pictures he posts. I usually log on to his site once a week or whenever I know he's spent some time on the site just to make sure he's staying within his limits.
We are also youth leaders at our church and I maintain our youth group's page on Myspace. In that sense, I help other parents monitor what their kids are posting as well. I've told the kids flat out that if I do see anything inappropriate (including forwards or bulletins that didn't necessarily originate with them but that they shouldn't be posting/ forwarding on, I will have a chat with their parents). If it's something mildly offensive, I usually send them a message as a warning to let them know that I am watching and ask them to delete what they've posted. If they don't delete it or post anything else offensive, I have a conversation with their parents. I've only had to have two conversations with parents and there are about 50 kids connected to our youth group's page. It's easy to post pictures of our latest trip or event and is great for keeping kids connected since so many of them use Myspace every day but they don't always check e-mail. We post all of our announcements on the site and it gives us the easy ability to send messages to kids & parents (we have quite a few parents who have pages too!) to let them know we're out there and interested in what is going on in their lives. And it's a great tool for keeping up with birthdays!
By the way, the youth pastor and pastor of our church also have the username and password information for the youth site and we've given out the site address to parents in case they want to check it out as well. I also encourage other parents to get a site as well if their kids have one. The more parents that have sites, the less likely the kids are to post dumb things. Some of them think they are anonymous on the web but they're not and if more parents would show their kids they are watching, I don't think there would be as much junk out there; and as much fear from parents for that matter.
I am not a fan of keeping kids away from the internet since I think it is a vital point of communication and business in our world now. Kids have to learn how to use the tools out there and how to be safe with them; complete denial of use doesn't teach them anything except that you are fearful of new things (way uncool Mom!).
So my suggestion: you and your daughter should sit down and create your pages together and learn how to use social networking to your advantage.
By the way, Myspace does have an age restriction of I think 15 but there is no way for them to check ages so as long as a kid enters a birthday more than 15 years ago, they can get a site. I'm not sure about FaceBook. So it is a bit dishonest for kids under 15 to have a site. I am not a follow-the-leader, jump-off-the-bridge kind of parent but based on how we use Myspace, I do not see that it puts my son in jeapardy and I realize what a great tool for keeping in touch with our youth group it is. Quite honestly, it gives our son and other kids a social outlet and allows me to really see what's going on with them without having to design and maintain a website they wouldn't frequent that often.
Good luck!