She raced to look for him during Water Seven.
The two even had a nice shift of this dynamic during Enies Lobby, where Nami would protect Sanji when he found himself incapable of fighting Kalifa.
It was once said that Nami is the ship's captain the working one, don't remember exact words or the source, either SBS or data book.
As much of a trope being the swooning, ladies man is in anime looking at you Brock , it at least highlights interest from the character, and Sanji has expressed quite a bit of interest for Nami.
I absolutely love Nami, she's in my top 5 of favorite One Piece characters and I understand the crew would be dead 100x over if she wasn't around.
3 Sanji: A Clear Romantic If there was ever something going against the pairing of Nami with Luffy, it is the pure fact that Luffy near perfectly plays the innocent, disinterested, possibly asexual character.