How to explain a miscarriage to a child

I have an 8 year old daughter who is counting down every day, asking me if it’s safe to eat this or that, always wondering how I’m feeling and waiting to find out it she’ll have a brother or sister.

I just got confirmation yesterday that I am having a missed miscarriage & baby stopped growing after my last US 4 weeks ago. How do I break the news to her without breaking her heart? She is very mature for her age but is also extremely sensitive. This will be the hardest conversation of my life 😓