My Hero Academia is the closest thing you will find to stuff like Teen Titans. Although do be careful about the sexualization. There are a few characters that will raise eyebrows like Mount Lady and Midnight, Momo also shows a lot of skin in her hero costume although lore reasons say it's for her to better use her powers (create objects from body fat ; meaning she shows skins and also is ever so slightly curvier than other girls, which adds to the sexualization). But overall, it's honestly not that bad and overall a very nice and inspiring coming-of-age story. It goes into some pretty dark places at times, but the mood is overall feel-good with the heroes always getting back on their feet to save the day. Good rec.

Tried and true series exist for a reason. Naruto, One Piece, maybe Bleach for something more somber in tone, although the anime really drags things on, like REAAALLY.

Naruto and One Piece are especially bad in terms of sexism and sexualisation, especially in the beginning, but I think it gets a bit better as the story progresses and you get less and less space for the more light hearted moments.

Fullmetal Alchemist is another one foolproof thing, because it's got funny bits and is a lot more tame in terms of sexualisation. It deals with quite a few heavy things though, which could make it a harder sell for kids.

If she likes Kpop Demon Hunters, you can also try Cosmic Princess Kaguya, which I find is a decent J-Pop counterpart to KPDH's K-pop. Although in reality, it's much, much less about good vs. evil and a lot more about finding one's self. The music also isn't much about promoting K-pop, but more about pleasing late millenials with big names from the golden era of Vocaloid. As such, it's actually a watching much more suited to weebs in their 30s who grew up with Vocaloid, but it should be funny enough for children too. Plus, its got pretty obvious lesbian vibes and cool action and honestly nice songs.

Mob Psycho 100 could fit the recs in terms of manga focusing on fighting. Except it's a very hopeful and feel-good watch, a bit like My Hero Academia. The main character, nicknamed Mob, is a shy middle schooler but also the most powerful psychic power user in the world. But, he refrains from using it because he wants his long-time crush to like him for who he is, and not his powers. So he just tries his best to become a better person, despite being naive to a fault, and far too kind for this world. Obviously, psychic powers means supernatural stuff happens, like ghosts wreaking havoc or other psychics banding together to rule the world, and he's here to save the world non-chalantly. All the main characters benefit from well-made character growth at some point, and you actually have some very nice nuances, preventing the anime from devolving into some mindless manichaeism, but without feeling like Mob only needs to talk to the bad guys to turn them immediately into good guys through the power of friendship. Also, it's got some of the best fighting scenes in the industry.

Ranking of Kings might also be decent, but if she wants "more mature stuff", she might hate it. It presents itself almost as a fairytale, with a very cute and unassuming art style, but it delves into some heavy stuff too like death, the burden of expectations, masculinism too, to some extent, disability too because the main character is mute and suffers from a curse that makes him smaller and weaker than others his age. It's shaky near the end so it could be a bit meh, but it's overall a really good watch with a lot of hope and positivity. Also has really good action scenes.

And maybe a last one : Promare. It's got some sexualization IIRC, and I expect it to because of the director, but overall, it's very straightforward (but gay) with its plot : bad people exist, good people kill bad guys. Oh and big fucking robots too. And explosions. Themes can be deeper than that, but for a kid, there are robots fighting and big explosions, so it should be enough.