Score

Not sure what was meant by the title/description 'Odd siblings -
Books that feature strange siblings', so I used my own interpretation :-)

Booklovinglady wrote: "Not sure what was meant by the title/description 'Odd siblings -
Books that feature strange siblings', so I used my own interpretation :-)" I guess odd in that the relationship is unusual or the siblings themselves are strange or unusual I am going to check out a couple of the books you have added they look interesting.

@Fiona
I know the book by Tessa de Loo (De tweeling) has been translated into English as The Twins.

Het smelt, Gitte and Broer haven't been translated (yet?), as far as I know.

There's an English edition of De engel van kristal (Crystal Messenger), Er zijn geen messen in de keukens van deze stad (No Knives in the Kitchens of This City) and Vogel (The Bird).

In The Mysteries of Udolpho it is of course not Emily I meant, as she has no siblings, but her father :-)

Although it is not gone into very explicitely, the relation between Rachel and Stacey (A Jest of God / The Fire-Dwellers) is on odd one too, in my opinion.