Advice for non teacher please!

[Jellyboobs]

Hi,
I'm helping out at my daughter's school once a week in the library. My group are years 3 and 6.
Today I was in there and some year 6 came in and were being noisy, mucking about, chucking stuff and not choosing any books. Some quieter children came in and we're a bit intimidated by it. No one was rude or violent, just usual kid stuff, but I have no experience of children that age and would like some advice on doing the best I can with them and for them. Thank you!

I would quietly and calmly start talking to the quieter children and ask them about their book choices. Give positive attention to what you want. Praise the children who are behaving well.

If you feel ok with doing this, I would approach the bad behaviour directly. I don't see why they should spoil it for other kids?
I would take down their names, approach their teacher and if their behaviour continues, they should temporarily lose a privilege or similar.
Low level behaviour can be just as disruptive and other kids shouldn't feel intimidated.

Brilliant, thank you!
What if it's just the noisier ones? It's a small room, no shelves just books along the walls, so we're all in together.

Thank you super pug!
Two of them actually came back in, all affronted and asked if I'd reported thrm. I hadn't but two of the girls in their class had.