I might be off by saying she has no chance of reaching him. Hood's ranged attacks is by stretching his body, she could just grab onto him and
run up him like she did here. Though Hood can avoid her attack or cut his own limbs off. She actually has a better chance than I initially thought, especially since she can break out of his grab.
She also doesn't need to kick his head off, if she grab it I don't think Hood could push her off before she rips his head off. She could even grab his stretched limbs with her legs and slam him down into the floor if she wanted. Wouldn't crush his head, but it'd bring him down to her level.
Have a massive bias for Mirko so I want to believe she wins.
You know what, I'll play devil's advocate here. I think Mirko can actually take this. But I think she can pull a win here. Her attacks are up close, as such she'll need to go up to Hood. She's mobile and skill enough to avoid his attacks, and was shown to be able to rush up a High-Ends' limbs with ease.
Hood's also not going to just play the range game forever. He'll charge her as well, considering the fact he charged Endeavor who was charging up his attacks. He's just as battle crazed as her and Rappa after all. He'll take extra care to avoid getting his head kicked off, so I don't think she'll just be able to kick through his brain.
I do believe she can eventually get a grip onto his head and tear it off of his body. His only method of ranged attacks is by stretching, so he'll always be making a path for her to climb up to him if he attacks from a distance. And she could escape his grip if he ever grabs her. Wrapping her legs around his neck would be easier than kicking his brain.
Also, she could separate his head from his torso with a kick. While that alone won't kill him, he'll be immobile for a second as he's healing and can't fly without his shoulders.
While they weren't as smart as him, she was able to hold off three High-Ends at the same time without taking any extra damage either (While missing an arm). I also imagine having to fight three of them at once made it more difficult for her to focus on a single one to hit. Which could contribute to her struggling to hit them as well.
She can't fully commit to a hit because she's being harassed by multiple enemies after all. She has to make sure to avoid their attacks at the same time.
Against a single High-End, she only needs to focus on him and has no other distractions. She's also in peak condition as well.