I have never watched the filler Hanare is in, but design wise Kariya is plausible as her and Kakashis daughter. I really like the casual dress she wears, it's very cute and practical, without being too over the top cute. I like how her ninja outfit is a mix of her parents styles. I love how you didn't have Kariya always wear a mask, because based on canon it seems to be a personal thing for Kakashi, not some clan tradition or something, but it does make sense for a ninja to be masked. I really like Kariyas hairstyle, it suits her well. The beauty mark under her eye is also very cute and suits her well.