Hey There! The category can affect the outcome of a Kickstarter campaign as people interested in backing certain projects will search for those via the kickstarter platform (and in some cases, only on the categories that they are interested in). As Hyperstarter said, your project can potentially fit into more then 1 category, but finding the right one can be a confusing process sometimes.
The category you list your campaign under can affect the outcome depending on how you are marketing your project and who you are marketing it to. I do think that fashion is the right category for your project so I wouldn't worry too much about this.
Feel free to get in touch if you have any other questions
Best Regards,
Jake
Team Backertree!