✨A Heimdall AU redesign named Heiðrùn✨
Personal HC is that there'd be some difference between the two. Based on how she'd be treated as a daughter, sister and woman in general(the Aesir are sexist to some degree, you can't change my mind). This includes the name given at birth.
Relationships that would shift for the better and the worse, due to different circumstances. For example, being somewhat closer to thrud, Sif and even Freya, due to their shared difficulties, and lack of respect from Odin and inner circle. Thrud and Heiðrùn aren't suddenly besties, but a sense of solidarity is there.
Her expertise more on political manipulation, espionage, magical prowess and concealment(Odin condescendingly figured she'd have "to play her strengths"). Gjallarhorn is carried, but permanently hidden with bifrost magic, like most of her weaponry. She wasn't permitted the same rigorous training like her brothers, but did so in secret nonetheless, even if it was just to prove her worth.
Therefore Heiðrùn is pretty stacked and expertly combat trained , especially in comparison to how slim and sloppy of a fighter Heimdall is. Kratos would struggle way more with her, considering he mainly bested Heimdall on "spear go boomski and cause a big confuse" and being faster than he could dodge.
Ngl this started as a blatant "femdall can throw me off Hrimthurs wall" type of yassify art, but my brain went brrrr😂