So.
Resistance Leia doesn't actually have a timing.
After a friendly ship reveals its dial, you may spend 1 force. If you do, the chosen ship reduces the difficulty of that maneuver.
The itnention is presumably that the reduction only happens for the given manoeuvre's single execution, but it lacks any endpoint for the reduction. Which is complezx partly because a number of effects call on the difficulty of the revealed manoeuvre, and Leia doesn't say when the revealed manoeuvre STOPS being reduced in difficulty (i.e. does Cova Nell still count it as the difficulty it was executed at?), and partly because...
Decrease the difficulty of your speed 1-2 basic maneuvers.
(The lack of wording consistency of decrease versus reduce aside, c'mon FFG seriously) R4 astriomech uses the same wording. There's a strong, albeit clearly not intended, argument to be made that Leia's difficulty reduction is currently, permanent. So, if Poe reveals a 4K in round 1, and Leia makes it white... when does it stop being white? Currently, never. It's white for the rest of the game, and nothing stops you using Leia on it again and making it blue. Nothing tells you when to stop reducing it, so you don't.
Let me be perfectly clear: this is clearly not the intent of the card, and I don't think it SHOULD work this way, and I think errata is needed to add a timing (either 'whilst executing the manoeuvre this round', or 'until the end of the phase/round' depending on intent). But I don't think it's remotely arguable that it currently DOES work this way, and anyone who says otherwise is assuming the existence of text on the card, that isn't there.