Long story, so in short, my sister has not been using iMessage. She had Verizon block messages and preferred to use Facebook Messenger. So then AOL has a security breach and she tries to change her AOL password. So they send her a code to SMS, which was blocked. So she removes the block. I tell her Verizon does not charge for iMessage text. She has no text plan. So I go to send her an iMessage and it's green. She said it was turned on. So then I see that it's tied to her email address, rather than her phone number. Everything looks correct in send and receive. What does she need to do to get iMessage on her phone number? Does she need to sign out of iMessage, then sign back in? If so, in what way? Thanks!