A Shower Or Not????

Here`s the dillema, my sister had a whirlwind engagement and was married within a month at a very beautiful but intimate wedding with just the immediate families. She is having a larger reception later this summer and the Sister of the Groom and I would like to throw her a shower as we were her attendents. The problem however is MOMZILLA does not feel that this is appropriate where she is already married and it would be very awkward. What do you think? How should we word the invitation if we do have one.