Kristen wore her TNA Buffalo Plaid Flannel Shirt, you can get something similar on Amazon
Her converse are vintage Bellaire, you can browse for something similar on Ebay
Her backpack is a Fjallraven Foldsack Backpack in Yellow, you can get it here
Kristen wore GYDA Lady's Military Jacket. Unfortunately, it's already sold out, but if you want to browse their website check out gyda.jp/ or send them e-mails for requests.