How rude is it....kinda long

My FMIL doesnt want any of her very large family to be invited to my Shower (they all live off LI and she doesnt even want my mother to send them an invitation). So my mother agreed and that is the way it is going to be...however...since my FI and I live together our registry was small and only enouhg to cover shower gifts. So...when it some to the wedding and when my Future inlaws especially call to find out about a gift registry there wont be one. (my family I am sure will give money since they brought gifts to the shower). What do I tell them? I am not making another registry with a bunch of things on it I dont want. What should I do?

Thanks!