Ok so I just found out how to get the Barbie shirt, but you have to hurry, because they're going fast!
People in the UK have gotten the shirt from a contest, but if you want it, jsut follow these instructions.
Go to any UK proxy, like slygeek.com OR goproxing.com
Then put this into the proxy URL box.
Wait until the page loads, log in, then change the proxy URL box, to look like this.
Wait until the page loads.
Now, you will be asked to fill in your full name, address and phone number. You DO NOT have to fill thi in properly, just write in some letters and spaces for the name and address, and for the phone number, just put in 0, or one number.
Click on enter the contest, close the proxy, go back to Stardoll as normal, and it'll be in your suite.