iOS 14 merging iMessages for 2 unrelated cintacts

My grown daughter’s iPhone 12 using iOS 14.7.1 JUST started merging an unrelated friend and me (her mom) when she is trying to message one of us. If I send her a message and she replies-the reply goes to her friend. Not me. None of us has the same Apple ID or the same telephone numbers. She doesn’t know who is getting the reply. She tried deleting contact cards and creating new ones, deleting message threads and starting new ones with both of us. Nothing works. Can anyone suggest a remedy?