Well it's a good thing it's not her wedding or she would be paying a fortune, OP.

Did she see her reflection in the plate?

Why is she butting in on your wedding planning? It's not coming out of her pocket, and it's also not her wedding.. Whatever you and your future wife likes goes! Congratulations OP! Have a wonderful and beautiful wedding!

There's a word you need to say to her. It's two letters long and easy to pronounce: "No."

umm no. she can consume a bag of well you know

OP: "Ok sure. If you agree that we never bring your future grandchildren around!" Best way to kick off a marriage!

I really hope you said NO. It's your wedding, your life and your money. If she doesn't like the plates, too bad!

Well OP, if she says that you need to replace the plants ask her to fork out the money to replace them and have her sign a contract saying that she can't come after you for the money. Seeing as the plants are a gift from her.

Tell he she can swap the plates if she pays for them herself.

Really, OP. Stand your ground now, or it's going to be like this for the rest of forever....