Announcing to someone going through a loss?

Hi ladies,

Our friends recently announced they were 4 weeks pregnant to us. I am currently almost 10 weeks. We were going to announce to them that i am pregnant at 13 weeks because we are more hesitant due to a previous loss. we found out today that she had a miscarriage so we are no longer telling them at 13 weeks as we think its distasteful and we want them to have time to heal. We feel so bad for them. I know how it feels and its the worst emotional pain. The only thing is, we planned to announce on social media around 14-16 weeks. We dont want her finding out on facebook. We thought about postponing that longer but at the same time, we are excited about our pregnancy and dont want to hide it from our friends and family for too much longer. When do you think is the right time and how would you guys go about announcing to someone who is going through a loss? Thank you.