Yes, there are some. You can start by looking on popular fanfic platforms like Archive of Our Own. Just search for 'Harry Potter x Ms Marvel' and you'll likely find a variety of stories, ranging from crossovers where the characters meet in a magical multiverse to ones where they team up to solve a common problem.
Well, I've come across a few. Some of the 'Harry Potter x Ms Marvel fanfic' are really creative. They might blend the magic system from Harry Potter with Ms Marvel's superpowers. For example, in one I read, Ms Marvel gets transported to Hogwarts and has to learn magic while also using her own abilities to deal with threats in the wizarding world. It's a really interesting take on mixing two very different universes.
There are definitely some out there. A lot of fanfic writers like to explore crossovers, and this one is no exception. You can also check fanfic communities on Reddit or Tumblr. They often have discussions and recommendations for 'Harry Potter x Ms Marvel' fanfics. Some stories might focus on the characters' relationships, like how Harry Potter and Ms Marvel would interact and become friends or allies, while others might be more action - packed with them fighting against a common enemy.
Chapter 592, "The Secret of Dragon Ridge Lake", is the clearest early answer because the hidden truth stops feeling like mere subtext. The setup is Hmm?" Jiang Li's unexpected question left Zhao Lang somewhat..., but the pressure keeps building through There must be something wrong with the lake..
Chapter 635, "Forced Return to the Time-Space Administration", is the clearest early answer because it pushes Su Yinwan into a new phase or setting. The chapter turns that into something concrete by moving from But Pei Ye was much quicker than she had imagined.
Chapter 866, "Why don't you die in his place?!", is the clearest early answer because it turns Don's situation into a concrete plot event. Early on, In Shuiyun Temple, Changqing silently watched everything happening in....
Chapter 719, "Borrowing Their Luck", is the clearest early answer because it turns Chang Rong's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Chang Rong: "Hmph, it has nothing to do with me anyway, since no one...
Chapter 697, "This is Plagiarism!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. It opens with But despite all precautions, they failed to prevent it. and closes on Xiao Ye wiped her tears and looked at her imploringly, "Miss Jiang,....
Chapter 558, "The Love-Struck, Flirty Wife Appears", is the clearest early answer because it turns Xiao Chun's situation into a concrete plot event. The setup is These people's comments are just too unpleasant;
Chapter 1 is the strongest chapter-level answer because it starts from Jiang Li, I'm warning you, don't set your sights on Yinwan anymore, or... and follows through on Yet before she had the chance to teach her a lesson, the male lead arrived....
Chapter 817, "Killed by Me", is the clearest early answer because the violence around Killed becomes final instead of hypothetical. A useful checkpoint is the way the scene starts with Jiang Buchen leaned against Meng Wanzhi's chest and thoughtfully...
Chapter 705, "Is She Her Own Destined Noble Person?!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter gives readers a real answer by opening on He Wen was made to laugh by Bai Lu.
Chapter 745, "I'm Pregnant", is the clearest early answer because it turns Shu Yan's situation into a concrete plot event. The chapter turns that into something concrete by moving from Several people finally met Shu Yan in the hospital ward.