i don't think you need to go into detail at all - my niece had seem me taking tablets, and using injections for the ivf - when we got our BFP and told her i was pregnant, she understood that a Dr had helped me. for our Gremlin, i'm not going to hide what has happened. we will, most likely, need to use assisted conception to give the Gremlin siblings, so it will be a natural progression. i am not ashamed of using AC, and will not hide it. there is no need for graphic or confusing explanation. simply "we need help to make babies, so the doctor helps us" is more than enough for a young child. but if my now 8 year old niece asks for more info, i'll check with her mum what she knows of natural conception, and elaborate from there...