<human>: I'm not sure if this is even the right place to post this, but here goes.

Tomorrow (Dec 4th) would be my parents' 50th wedding anniversary. In the past I have called or texted on their anniversary, but this is a milestone. The reason I'm at a loss on how to deal with this is that my father passed away a little over 7 weeks ago. 

He was not feeling well all summer, battling bladder infections, fatigue, etc. He went into the hospital mid September, we thought he was going to be okay. After several biopsies of a mass on his bladder, the verdict was it was cancer, along with an atypical leukemia. He was transferred to hospice about 3 weeks after entering the hospital and passed 5 days later. 

It's been extremely difficult for all of us. Especially my mom. She's very independent, but I know she misses him deeply.

I'm one of 9 children. A few months ago we had talked about having a party for their 50th, but nothing had been settled yet. Then he went to the hospital and we never revisited the topic. We've all been dealing with our own grief, so it hasn't been talked about at all.

I guess what I'm asking is, what do I say to my mom on this day? It was meant to be spent with the love of her life. I think it should still be acknowledged, but I don't know how to approach it. What would be an appropriate way to celebrate/honor their 50th anniversary, which has also become the first one without him?

Can you give me a shortened version of the text?
<bot>: My parents 50th anniversary is on Friday. Father died in October. How do I observe/honor/celebrate their 50 years together?