I was 6 when my little sister was born and I too helped with changing nappies, holding her, rocking her etc etc. That was a long time ago though.

My DD was only 15 months when DS was born and she was interested in holding him until it actually came time to do it. She found him really heavy and awkward and only tolerated a few minutes of a cuddle. We instead encouraged lots of pats on the belly and kisses on his scalp, tummy or feet. We also showed her how to hold his hand. That was enough for her.

With friends kids and families kids, I might be a bit relaxed after reading your post. If the child is over 5, I'm happy for them to have a cuddle without close supervision. I mean an adult would be in the same room but doesn't need to be sitting right there assisting. I let an 8 year old family member carry DS around at christmas time and I wasn't worried at all. In fact, I left her there with him while I went to get a bib. I never thought anything of it until her mother saw and commented that I was relaxed about it all.

I think it's an each to their own thing. You might feel differently once bub is here and see how everyone copes.