It is clear from the description of the Tallis family that appearances suggest this is a normal family without any significant signs of unhealthiness. However, upon closer inspection, there do seem to be suggestions made in the text that could point to an alternative reading that presents them as having various unhealthy aspects. Firstly, the way in which the mother constantly seeks refuge from the heat and the noise of family in her room, lying "supine" on the bed, suggesting she is detached and unaware of what is really going on with her family. It is perhaps this lack of maternal influence that results in Briony's innocence concerning the power of writing and fiction, summed up in the following quote:
A world could be made in five pages, and one that was more pleasing than a model farm.
Briony here revels in the power that writing fiction gives her, but she does not stop for a second to think of the way that fiction not only creates, but it can also be used to destroy, which suggests she has a very unhealthy innocence and naivety, which is of course one of the major themes of the book, as her ability to invent stories robs two characters of a life of happiness, and arguably impacts her own life negatively as well. These points suggest very strongly that the Tallis family, as perfect as they appear, do have aspects that could be considered unhealthy in terms of their relationships.