Prepare a themed fun reading activity to act as an ice-breaker and to tempt them to try new books.
This is a great idea for your first session. You are encouraging the children to sample the reading group format using accessible, fun materials.
It's also a good way to encourage children to try something new – to give another person's reading preference a try.
Also, by making sure that the group has access to a wide range of fiction and non-fiction, children will have all sorts of other paths to explore, too.
The children will see the reading group as a fun activity and will straightaway see that the library values all kinds of readers and all kinds of reading.
Have a look for ideas on children's book sites.
Get ideas from colleagues at work and on-line – and from young people coming into the library
However this is not the end of this situation. See what might happen next.