lost device

My daughter has lost her phone and we are unable to locate it. I am now trying to login to her account but are unable due to a 2 step verification that is attached to the device and number. I have tried to setup my number to her account and after doing so it says that an email will be sent to her email.......i cant access the email due to 2 step verification???

Anyone shed some light on this for me as i now have a new phone for her and cant sign in to her account on it.....