Kara is the ultimate potential women. She has great material, but DC consistently changes the character and can never truly settle on anything.
Peak Kara is hidden somewhere in a combination of Tomorrowverse, Batman & Superman, Injustice 2 and DCSHG. She should be a Superman with more of a disconnect from humanity given her being from an entirely different world, and unlike Clark, actually living within it for years. She is also decently temperamental and a bit more cocky/confident than Clark, trying to separate herself from him. If anything, she should be a reverse Dick Grayson, a character who is more like Bruce on the outside who adapts many of Clark's traits internally. She should theoretically have the surrogate parent relationship with Bruce that Dick has with Clark, her personality and upbringing should be a bit more in line with his - plus the Batman, angry teenage girl pair up would be fun.
They should also give her more relationships to play off of. Barbara Gordon is the most obvious pair up for the World's Finest women. Extra points if they make Kara a bit of a tech geek like the Tomorrowverse so they have something to relate on. Giving Kara the DCSHG brand would be cool, allowing her to pair up with more neglected female legacy characters around her age since she doesn't have a main group like the Titans or Young Justice.