These news probably has a lot of us shook. My heart goes out to Zack and Deborah Snyder in the time of their grief.
In regards to Justice League I’m certain that Joss Whedon know what to do and how to continue Zack Snyder’s vision for this movie. But that is of a minimal concern right now.
I wish the Snyder family all the best. I am sure that Autumn Snyder is patiently waiting for them in the afterlife. I’m sure they’ll see each other again.
If you want to give support to her (and at the same time give support to a good cause) then I direct you to this tweet from Zack Snyder:
https://mobile.twitter.com/ZackSnyder/status/476833577858920448