I’m sure it’s fine – once the cake is cut, the guests won’t notice there’s no fondant. If you want the display cake to look more impressive (to please the bride), you can do the bottom tier out of actual cake and the top one a dummie cake. That way she’ll have a two-tier wedding cake, which would look very nice – you never know who could be at the wedding who is impressed by the wedding cake and will call you for business.
DJ - Fun Fiesta Cakes