I suppose that, for most of us, the fascination of conjoined twins is that such people can serve as symbols.

My first book is about twins who are attached: two people who are joined and can't escape each other.

Conjoined twins are identical siblings who develop one placenta out of a single fertilised ovum. No cases of conjoined triplets or quadruplets have been documented.

I always had a fascination with twins.

After a life deprived of everything from romantic love to the choice of when to wake up in the morning, after 29 years without the ability to have a career or even to be alone at toilet, the Bijani sisters are not symbols but women who have had to live a shared life of constant, quotidian sacrifice.

I think it's a wonderful fact about Judaism - at least about the approach to Judaism I most relate to: There are no universal answers. We don't have it all figured out. God is unknowable.