@Olivia I had a misscariage 2 months ago and we didn't tell her I was pregnant but she came to the appointment I had in the hospital for a scan after the misscariage and she was questioning what a misscariage was, my daughter has autism so we don't like telling her to much information, she thinks when I'm pregnant she's pregnant too because shes my baby this is the reason I didn't want to tell her, I have a feeling she's going to ask today as she was saying things like " I'd love a baby brother"
I'd let her/him know basically what you said here. I feel like that's old enough to understand high risk and if someone else told them it seems especially like you're hiding something now. You'd have to hide a miscarriage too