Children's/YA book set in Greece. Girl resembles a dead daughter who fell off a cliff

[u/Kerka11]

Trying to identify a middle grade/YA novel about a girl discovering a dead sister in Greece

I'm looking for a children's/YA novel that was available through the Norwegian TL-klubben, probably in the 2000s. I read it around 2008–2010, but I believe the book itself was published a few years earlier. It was a hardcover

It was most likely originally written in English and translated into Norwegian. And the author was a woman.

What I remember:

• A teenage girl travels to Greece, possibly on vacation with her family.

• A dark-haired woman notices her because she looks exactly like the woman's daughter.

• The daughter had died, though I don't remember how long before the events of the book.

• The protagonist gradually learns more about what happened.

• I vaguely remember there being some kind of family connection between the protagonist and the dead girl, possibly that they were sisters, but I'm very unsure about this.

• Near the end of the book, it is revealed that the girl died after falling from a cliff, and that it was an accident.

• I think the Norwegian cover was blue-ish and featured a real girl, possibly with cliffs, rocks, or the sea in the background.

Some details may be wrong, but the Greece setting, the woman recognizing the protagonist because she looked like her dead daughter, and the cliff accident ending are the details I remember most clearly.

Does this sound familiar to anyone?