Who is Dr. (William) Hutchings from The River Between Us and what is their importance?

Dr. (William) Hutchings is Tilly's husband. He is described as quiet, responsible, respectful and determined. His initial attraction to Tilly comes as a considerable surprise to her, but it is welcome none-the-less. William's attentions prove to Tilly that, in her own way, she can be as desirable as Delphine.