In the opening scene of The Last Jedi we see the bombing run of the resistance take out the First Order Dreadnought. The only bomber who manages to destroy it is Paige, who holds onto a necklace before doing one more kick to knock the detonator down.
While we later see Rose has the same necklace (or one that fits together with it), that's used as a conductor of some kind to open a door.
However given the 3-4 second shot we get at the start of the necklace, Paige hold onto it as if it had some sort of power, and then find the courage to kick the detonator down, but after that point the necklace only features as a minor point as a measly conductor.
Was the purpose simply to show they were sisters? Do we ever learn more about the necklace?