"She claims that she had been there twice" - Past Perfect

Mi się też wydało, że zdanie, które cytujesz, powinno raczej lecieć tak:
She claims that she has been there twice.

A jeżeli już użyto had, to bym oczekiwał jakiegoś dodatku dla jasności:
She claims that she had been there twice
before she decided to organize the party there.

Ale... Kto wie, może powinniśmy uznać zdanie za poprawne, domyślając się, że wypowiedziano je w jakimś takim oto kontekście:
She claims that she had been there twice (before we went there together). I don't believe that she had been there before. When she entered the room and saw the paintings on the walls, she was terrified.