Her opponents reaction was typical, throwing up a wall to protect herself.
You know, blocking your line of sight of your opponent is generally a bad idea. Fuu would loudly state for Nezuko to hear, though with no intention of punishing her for the action, instead waiting to see what her abilities were.
Watching as Nezuko appeared above the wall, her arm transformed with a punch aimed directly at Fuu. In response, Fuu would calmly step back with her right foot into a fighting stance. She would then thrust her right hand forward, index and middle finger extended, to directly intercept Nezuko's fist; releasing a powerful blast of wind that would send her flying backwards through her own rock wall.
Please again note that Fuu does not require hand seals for wind jutsu.
Chakra:
2290 - 20
-2270 remaining.
For fights, it's best to be very descriptive about your jutsu. For instance, how large is your wall? The canon depiction of that jutsu is kinda big. Be sure to remember the time it takes for hand seals to be formed, and what of my actions you might be reacting to.
Also take into consideration your jutsu and other things on the field. For instance, I interpreted your move as you jumping over your wall, where as you could have meant you went around either side or even smashed through it.
Taking note of the details will help avoid needless quoting and move the fight along smoothly.