I think it would be nice if we saw more members of Tom and Rose's respective families. Besides his brother Kieran, Tom mentioned cousins on a few occasions. His mother we know was alive when he got engaged but that was the last we heard from her. One wiki contributer I know suggested he should have a grandmother or grandaunt to match wits with Violet. As for Rose, we know she has two aunts (unknown if they are still alive), a brother, sister, and brother-in-law.