If your girlfriend has changed the password to an email account other than your personal one, she will not be able to give you the new password. However, you can try this methods:1) Try reaching out to the email account that the email you are experiencing is located. If the email address you are using is still active, it might be possible to phone or email the email account that the email is located in order to get the password changed.2) Place a request on the email platform you are using. Sometimes, you can find out which account is used by which party.3) Even if the email account you are using is still active, you can try to call or email the person who is responsible for that email account.4) Even if the person who is responsible for the email account is not available, it might be possible to find out who changed the password in his or her account.5) Even if the person who changed the password is not available to help you find the password, you might be able to find out how to change the password.