She has the same ability as Kushina, let's not forget that. I do believe she can easily beat Hinata.
Yes she has the same chain attack as Kushina. And I agree, the chain is a very useful weapon. However, having the same weapon with a strong person does not automatically mean you have the same strength and capabilities of said person. Konohamaru holding a Kunai is nowhere near dangerous as Uchiha Itachi holding a Kunai. Yamato's Mokuton has nowhere near the same capabilities as Hashirama's. Hinata's Taijutsu attacks is nowhere near as powerful as Neji's. It's the capacity and level to which they can use it that makes the character strong. My point is that just because Karin has the same chain attack as Kushina does, it does not hold much significance in terms of power.
Furthermore, Karin's one offensive feat so far has not convinced me that she could take on a fight with an actual Shinobi. Yes, she made the Gedou Mazou crumble. However, if we assume that the Gedou Mazou is wood/rock statue, there have been many characters who could accomplish crumbling a wood/rock from when they were a genin. Naruto(rasengan), Sasuke(chidori), Kiba(Gatsuuga or Soutourou), probably Rock Lee and Neji, Chouji, Gaara and Temari. The reason why these guys are not doing this right now is because 1.) They are near dead (Naruto and Sasuke), 2.) They are attacking it from a distance, 3.) They don't have chakra, and 4.) They are not reckless to attack it head-on especially with 2.). Therefore, I don't see how Karin can be considered to be able to beat Hinata(a Chuunin-level shinobi) "easily" when the only battle feats she has shown so far was accomplishable by nearly more than half the genins we have seen in part 1.
If it was short-range, I can't see how Karin can beat a Hyuuga taijutsu fighter who has trained to fight Hyuuga style taijutsu all her life. Using chains in such a short distance is very ineffective.
It's the same for Mid/Long range. Hinata was able to dodge mokuton attacks from Obito, one of the strongest Ninja in the Naruto-verse. It's hard for me to believe that she can't dodge chains from Karin. Moreover, if HInata gets hold of the chains, she can flow her chakra into it, and close Karin's tenketsu prohibiting her from using chains anymore (like Neji vs. Kidomaru).