My daughter is 7 and we had the talk a couple hours ago. She thought babies come from belly buttons but now she knows babies come from girl parts and i explained that there's tummy pains that help make a big enough gap for babies head to come down and then when it's open enough mummy's push hard for a little while and then baby comes out. She actually took it really well and seemed to understand. When I had her brother 4 years ago we just told both kids who were 3 and 4 at the time that I get a tummy ache when baby was ready to come out then I'd go to hospital and they would take the baby out and look after me. I didn't think at that age they needed any more info. I only told my daughter tonight as we were watching animal hospital and a dog gave birth def not from its belly button, so I figured she asked why not fill her in. 4 year old doesn't seem to care how or when his sister is coming out he just knows she will be here when she's grown big enough. :)
My daughter was 2 when I was pregnant with my son n she thought that the doctor "put baby together" lol it was so funny. Both my previous children were via csection n this one will be too so she now knows that the doctor cuts me open n takes out baby. She loves seeing my csection scar :) not sure how I would explain vaginal delivery, But I say she is old enough that if u explain it truthfully, but leave out graphic details, and leave out any talkabout sex, Just say that baby is in ur belly n u will go to doctor n they will help u push baby out that might be enough to get her to stop asking questions. Make sense?