I'm not Riot, but she is definitely not fine.
- BoRK rush gives her more benefit than other carries rushing IE or Triforce (Sustain as part of build path, cheapest item of all three, and a solid active ability)
- Despite what was supposed to be a late game carry/tank buster, she doesn't have a weak early game at all, she can easily get some kills early on thanks to her passive. (The fact BoRK has a very easy build path with some immediate benefits doesn't help either.) She also deals just as much damage to carries as she does to tanks (which is a fair bit) and is extremely good at dueling.
- While other carries don't start heavily picking up momentum until their second item (boots excluded), she picks up momentum after picking up one item (BoRK.)
- Her passive lets her chase a bit too easily, and her ult makes it much worse (90 Movespeed boost at r1 is insane, made even worse with a stealth dash/tumble. It's pretty difficult to peel her off if she's gunning for you, especially if you lack hard cc.)
- Is even better at ambushing champions in the jungle than Teemo.
That said, before she gets some serious nerfs, BoRK probably needs nerfs/changes as well (namely it being such a good rush item on several champions asides from Vayne, not to mention being a very good item in general. She may need nerfs after too, but BoRK is the best place to start since it makes her early game weakness basically non-existent.)