Hi Becky,
You could try revising your workflow so that your team member doesn't approve the email until it's finally ready to go. They can work on it while it's in draft mode and send sample emails to anyone who needs to provide feedback on it. The email should never be approved until it is actually customer-ready. This way, if she forgets to approve it, the email simply won't send. An unsent email is better than one that was sent with errors.