I hope I can explain this because I really need help!
My dd has an iPad and we set up an account on it for her. We recently bought an iPhone now she’s getting the bus to school. I can’t work out how to connect her phone to her Apple ID, so that she can use iMessage and not just sms text. I’ve tried googling and it says about putting in her phone number so that it’s part of her Apple ID, but I can’t see how to do that. I have set up family sharing, so that I have access via my phone and I wonder whether this is affecting it. Thank you for any help.