For Nu i find using j.qcf.b ~ d works well to counter swords. You have to OTG the projectile so you are basically in the deadspot where her swords don't hit. that should give you time to close the distance on Nu. This usually works well. If your timing is off on the projectile you end up trading hits which isn't all that bad since yours nets more damage.
I play a sort of zone/counter style of Rachel and this usually works for me. You can also wind accel. her qcf.b from the ground which will hit about head height and if it misses it lands right about where she will back dash to setting up a detonate.
