My wife's iPad uses her email address but comes up with my name

"but comes up with my name" - what do you mean by this? Comes up where?

iTunes accounts (where you buy music, apps, etc.) are not the same as an icloud account. If your wife uses her email address (this is the Apple ID) to get updates, then that implies her itunes account is the one using her ID.

I suspect that your name coming up (again, I'm not sure where this happens) may be that she is using your ID to log into icloud. Otherwise please describe your issue in more detail.

That doesn't make sense to me. If she is using her Apple ID which should be her email address, where is your name coming up? Where is she seeing this?

If you mean that the iPad has your name on it, you can change that in Settings>General>About>Name.