Hey there MummaB

You might find this article of use...
https://www.bellybelly.com.au/birth/siblings-at-birth

My mum had my 15 & 10 year old brother at the birth of the twins and it went great for her, but there is quite a substantial age difference so i guess not much comparison! I can tell you though the boys were proud as punch to say they'd seen a real live birth, they found it quite impressive.

Hope you can get some better answers from others!