Recently switched phones and I gave my wife my old phone (Storm1). When she text messages it says my name as the sender. Everything has been switched over, phone #, contacts, email addresses, etc. For some reason the text messaging function still thinks the owner of the phone is me. When she sends a message it does come from her phone #. The problem is only with her display name in the phone itself.
Is the conatact information in the phone (your information) changed? If hr device has a contact for you and the number for you is your old number then that is how it will be displayed for her.