Powers & Abilities Nami will get conquerors Haki

Each main female pirate of the last eras has conquerors Haki; Big Mom and Hancock. It only makes sense that the main female pirate of this era has it as well.

Oda has also hinted at it in a gag in Wano where he juxtaposed the scene of Luffy knocking out everyone in the prison with Nami knocking out the bathhouse with her happiness punch in the same chapter.