Fiora is not the biggest of your top lane problems.
That title belongs to
Satan Teemo.
But in all reality, Fiora cannot take any punishment. Go up top with Sion; you'll change your tune if you know what you're doing. Fiora may deal tons of damage, but she has no cc at all. She has her parry/counter, she has a small dash thing, but she can't stop you from just walking away. If you stand back, she can't get to you. She can dash twice, but from there she has to kill you if you fight her. There is no middle ground. Unless flash is up, she just also burnt her only escape going in. So if you're playing a champion like Sion, you put up your shield while she starts chipping away at it, you charge your q. Not to mention that, if she gets her AD high enough, she can near-kill herself by ulting you. I did that once; had like 6000 HP, thornmail, randuin's omen, warmog's armor... She ulted and took a ton of damage. I didn't take much at all by comparison. Even if she builds black cleaver, that doesn't help her survivability a whole lot, and when you have all of those items and then some, it's like trying to knock down a brick wall covered in 2 feet of ice in the freezing cold with only a shovel.
Why else do you think you don't see Fiora so much in higher elos? She has a horrible reputation for getting caught out and dying, because she's a 1-way champion; one way in, one way out.
Oh yeah, speaking of Teemo, if you want to see something hilarious, pick Teemo into Fiora; see what happens when you use Zhonia's on her ult; it's hilarious.