Horrible timing!

I haven't gotten to tell my parents yet since they have been out of state with my sick grandmother. Just found out today that she has a cancerous tumor in her colon. I am at a loss for when/ how to tell everyone now! I want everyone to focus on grandma, I don't want to draw attention from this but I have to tell my mom soon! Help! (Ps first grandbaby on my side of the family- mom will be thrilled but this is her mom that was diagnosed)