Texting problem.. text message reappears in text box after it sent

[AC Question]

My mom has a Samsung Galaxy S3 and she is having a problem with texting. Sometimes when she sends a text... a copy of the same text she just sent will appear in the message box. She has to erase it to respond to whoever she is having a conversation with. I know it's not that big of a deal.. just kind of frustrating to her. Any one else having this issue or does anyone know how to fix this? Thanks!