Due to some stupidity, I forgot to renew my plates several months ago. The other day, my wife was pulled over and given a ticket for this. Since the car is only in my name and it was my responsibility to renew the plates, does she have any case to fight it?

Not really. It's the responsibility of the person driving the motor vehicle to ensure that all of the required documents are in the vehicle as well as that it's mechanically safe. ie Brakes, lights

All of the charge wordings for that offence start with: "Drive motor vehicle-...." Not "Owner of motor vehicle"

Funny how that principle went out the window with red light cameras.

Usually if you get the licence plates renewed, and then go to the court and show that you got everything fixed the prosecutor will drop the charges.

Do option #2 on the back of the ticket, to have a meeting with the prosecutor, bring the ownership with the renewal sticker on it, or the receipt showing that the fee was paid.

99% of the time the will drop the ticket for you.