I don't think so.
This has been raised by an issue by other users too.
One work-around is for each of you to use a different app for emails - so one use gmail and one use stock email, or venture into alternatives like K9.
This means that you will only see your emails when you go to your chosen app, but it does mean that your wife can access your email account by going into that app too - and vice versa.
You could restrict access to apps using the profile manager, but that would just lock one person out. Any administrator could change their profile access if they wished.