Good Morning,
I want to let you know that beyond the obvious of sympathy and sorrow that I feel for your family and each of your individual losses experienced through this tragedy, I wanted to tell you my viewpoint from a personal level.
I have not been on this thread for a long time now. It is funny how God points you in the direction to help yourself or others and sometimes my big mouth is quiet enough to hear him.
Though my family did not experience a death -they did manuvere their way through a tragedy last year and in short order we had to decide to go forward with our trip or forgo it as well. There is the practical side that wants the "perfect" time at WDW, the part that feels like you are maybe pushing a trip that isn't meant to be and there also for me was a significance in knowing that others might question my judgement. (You are here asking opinions and even those not Dis Fans at home share them under the guise of advice.)
Forget all of that and listen to your own heart and your SIL's. There is no guide book on how to heal the best for yourself. There is also no way that this loss will not affect your trip and time there. Now, 2 years from now or 10. He will never be back, there will always be a seat at the table at Thanksgiving not occupied that should be and this "place" is your new norm.
That sucks. It just does. No sugar coating here and no passifying you with tales of it will get better. Better would be if it never happened.
What it does get is a value and a recognition and a daily testement to his life. It gets appreciation and respect and his tragedy will impact others through his story and your dedication to not try move past his death. Carry him with you and enjoy what is good about every day and every moment. This will change you and her forever but some of those changes are good and even great if you allow yourself to feel.
Just with your short intro to what happened to him you have reminded me of gun safety. That is a gift his life has given to a complete stranger in an instant.
You will be in line with people at WDW and you will get to talk to them and the subject of the fact this is a healing trip for both of you may come up. I guarantee that your family's story will impact others. Maybe they won't be in such a hurry to each ride and slow down and see all the little things that make Disney so special. Maybe your story will help a Mom not have a meltdown when her ADR's have a 20 minute wait and that alters her perfect "plan," because now she gets a little bit more what is important and what she should just let go.
I appologize for maybe overstepping my boundaries of what you are looking for here, the short answer is yes - please go.
But the truth for me is one of a personal level and one I am still trying to work through every day. Looking for rainbows amongst the ashes if you will and they are out there. Brilliant and beautiful if you trust enough to start looking.
My TR is below and it may help you understand a bit more about my situation. The difference between us is that my son lived through his tragedy but in a few seconds longer or if he was standing an inch more to his left, he easily could not have. That has given me the blessing of having him here to tell me about how he wants to live his life and ours.
Your brother is not physically here for you to listen to but I would bet everything I have or hold dear to me that he is still telling you loud and clear. You just have to be strong enough to be quiet and listen.
I will be thinking of you and your family,
Dawn