It’s almost too much of a coincidence: two first novels within six months, both written in the voice of a young person with leukaemia who has been given months to live. Both are brave books that make the act of dying part of life and introduce young readers to the rollercoaster existence of families coping with terminal illness.

Tessa, 16, in Jenny Downham’s Before I Die and Sam, 11, in Ways to Live Forever by Sally Nicholls receive terminal diagnoses soon after the books open. Tessa chronicles her last nine months and Sam lives for just four. Their stories share a pattern of good days and bad, and of strong personalities asserting themselves in a world shaped by distressed parents, invasive treatments and debilitating medication. Tessa and Sam fight off powerlessness by listing the things they want to do before they die.

Stroppy Tessa wants to have sex, go clubbing and shoplifting with her friend Zoe and drive her dad’s car under age. Sam has a younger boy’s wish list which includes riding in an airship, going up a down escalator and seeing the Earth from space. He gets most of it done. The book itself is Sam’s creation and his memorial. Not published until January, Ways to Live Forever seems likely to have a bold graphic scrapbook format.

Both books are telling a story to which most readers know the ending (the penny might drop more slowly for younger readers of Ways to Live Forever). It’s not enough to move readers to tears (a likely outcome), stories like this also have to make them think, laugh and get angry and the authors here succeed in this to some extent.

Jenny Downham sets herself an extra challenge, by making Tessa tell her story up to the moment of death. The writing isn’t quite strong enough to carry us through this long-anticipated narrative peak; Tessa is more herself when she’s throwing her clothes out of her bedroom window or sabotaging her father’s radio broadcast.

But everything we learn about Tessa and Sam’s short lives rings true: the positive and negative effects on the whole family, the problem of too many well-meaning well-wishers and the importance of outside support. Both books are about more than death: they are about relationships enduring under strain and the impossibility of family and other loved ones always doing the right thing, while recognising that nothing done from the heart is really wrong

Before I Die

Jenny Downham

David Fickling Books pound;10.99

Ways to Live Forever

Sally Nicholls

Marion Lloyd BooksScholastic pound;9.99 (January 2008)

10-plus