What exactly do you want to read into that? Some people do confess when caught. She doesn't have to sneak around because you found out and didn't do anything about it.
Did she say she would stop immediately and wanted to try to work on the M? Anything less means she is continuing to cake eat. And even if she does say that doesn't mean it's what she's doing.
If you love somebody, set them free. http://tinyurl.com/2empx2g