That's a pretty negative outlook, it might be easier or harder to play effectively vs her depending on the match up but it's not impossible, spacing is important, like with any champ that has ranged/pseudo ranged harass, you will want to create situations for Fiora where using her Q might put her in a bad spot or be ineffective, the target needs to be visible to Fiora for her Q to target it, so using the brush can help you avoid damage while you get CS. If you can predict her dash you can juke it so that she doesn't hit a vital and have a better chance at trading back damage or use a knock back to deny the dash safely since she cannot cast Q and W at the same time. She is very vulnerable without W, so if you can bait out this ability and then re-engage you can generally have a much better chance at winning a fight. Also, as with many lane bullies it is sometimes best to just avoid full on fights with them, focus on the CSing as much as possible and don't push the lane if you are on a scaling champion, or push and roam if you are on someone that can provide early pressure, if you are intent on fighting her in lane then work around her W, it's like a game of chicken, during an engage try to either catch her off guard by using your CC before she has time to react with W or bait out W and then CC her.