I don’t think there’s anything unethical about hooking up with her in that situation, because she wanted to do it and she got drunk on purpose because she didn’t want to feel guilty.
The only thing unethical in my opinion, is the girls that do that (get drunk to fuccc) on purpose, and then blame the guy later and try to get him in legal trouble or accuse him of “rape” etc when she clearly consented But was just drunk/tipsy. With that said, I think that you did the smart thing by not hooking up with her, because it could have ended badly. If she really likes you, she should do it sober. And if you just want to have casual sex with girls, you can always do it on tinder, where at least you have something in your defense, if they met you on tinder, they obviously wanted to hook up.