When do you tell your child your expecting??


I have a 5 year old who is dying to become a big sister! Her wish has finally come true but when do We tell her?? I want to surprise the rest of our immediate family with her announcing on a shirt but don’t want to jump the gun. So any advice/ideas. I waited til I was 8 weeks for immediate family last time and 12 weeks for everyone else. But I know if she knows everyone will!!