What should I do with these gift!?

So it probably sounds like i'm just ranting today but I just got a call from my MIL letting me know that there is not going to be any Christmas family get together at her house this year b/c 1) My FIL ped away in June and my Sister in Laws can't 'stand the thought of having Christmas without their dad' and 2) my niece is due to have her baby on the 28th and doesn't feel she should be out that close to her due date. Well thats all fine and well but I already have ALL their gifts! I wish they would have gave me the heads up before I spent all this money! So what should I do with their gifts? Is there any gift giving ettiquette for people that don't show up to except their gifts?