Can't change shipping address?

So I let my sister borrow my account for a few days and after she was done with it she gave it back to me. Anyways the other day I tried to order something and I saw that she deleted my shipping address and replaced it with hers, I decided I would just change it back to my details by clicking on the edit button at checkout. But when I click the button nothing happens!?! I also tried to do the same thing from the settings page but I had no success. Any suggestions to why it wouldn't be working?