In fairness to her, as an actress, the idea of Ripley that A:R presented was fresh and new. It's hardly surprising that that's what she'd hone in on - Ripley is of course the most important aspect to her. The script, while clunky, was nowhere near as grim as what ended up on film. All the wrong elements were brought to the party, alas.
Anyway, it's nice to hear her thoughts, and I shall be interested in her reaction to the finished film. She's every bit as important as the creature to the mythos and it somehow feels right that everything should have her blessing.