Who are Solly and Hannah, and how does Toby describe them?

Solly and Hannah are Toby and Rachel's children. Solly is nine, and Hannah is eleven. Toby describes Solly as agreeable and kind, while Hannah is quickly becoming a teenager, especially in the sense of her attitude. Additionally, Hannah not only acts like Rachel, she also looks like Rachel, while Solly much more closely takes after Toby in every way.