No fight here. You can do whatever you want. But think of this also:
Why not have TWO (2) tax-free deductions instead of ONE (1)? Wouldn't that help your tax burdon each year? I don't know about your 403b so maybe there are certain advantages but it would just seem to me, even if you think you're set, to have more tax breaks RIGHT NOW, and one of those is to have everyone in your house snatch as much $ as you can away from IRS.
I make much more $ than my wife but she is still in her own 401 at her place of employment. Sure, she doesn't contribute much or will ever get much out of it but, you know what, it helps my tax every year.
We also have our own Roth IRAs also. It will help on our taxes and retirement later on.