It terms of writing it is ok, a mistake or two but nothing terrible.
However the content itself feels a little lacking. You only replaced Jaune with his OC sister without any real change in the events. The first chapter started off well enough with Joanna's reaction to Jaune's death but everything since then is a by the numbers rehash of the series only with less detail then the show itself.
I have no problem with replacing Jaune with you OC Joanne but only if she brings something different to the table then what we already have in the show itself. As of now rather then the goofy Jaune seeking to improve himself, you have the sullen Joanne acting as a sharpshooter. Explain why Pyrrha felt the desire to have Joanne as a partner. What differences she made in fighting the deathstalker and nevermore. Don't just leave it to our imagination with a line or two.

Wow using the edgy "hardened" badass is just bland and really boring with the part of Joan assisting Ruby being completely unnecessary.

LOL XD that reference to immortal XD

interesting story.

This has to be the first fic ive ever read to start this way, simply amazing. Please continue

So I haven't read the story yet, but aimless and rudderless mean the same thing for your sentence. You basically said without direction.