How do you explain the death of a close grandparent to a 5-year old?

My mother-in-law fell backwards yesterday in front of my daughter and although she got up and sat down just fine, a few minutes later she lost her speech and strength in her movements so we called an ambulance and they took her to the hospital.

While I was driving to another hospital to pick up my wife (my wife tried to protect her mom from falling so she fell over my wife, hurting her foot), the hospital where my mother-in-law is at called asking if they can do a surgery that could lead her to become in a vegetative state (nothing done would have killed her due to a massive brain bleeding).

Since I was driving, my phone was on the loudspeaker and my daughter got desperate because she doesn’t want her grandma to die. We’ll hear about the results of the surgery in a couple of hours but in case we get bad news, how can I break it down to my daughter?

My mother-in-law unfortunately was openly atheist that celebrate Catholic holidays such as Christmas and Easter so I can’t say tell my daughter that hopefully, we’ll be able to see her again in the resurrection of the dead.

Please help us.

How can I tell my 5-year old daughter, if it comes to the worst, without ruining her faith or having her breaking down?