you can sign just Kathy if you want, but I suggest you add something to it to make it more unique. I just sign Nolan, but the way it is written is not normal script so I know that another Nolan will not inadvertently sign in the same manner.SO although your signature is pretty (I do like it), it is too close to normal script so another Kathy could easily have a very similar handwriting / signature to yours.Remember your signature is one of the 3 elements so it MUST stand out and be memorable
I have such an awkward name and surname to try create a unique signature , I have tried so many different ways, in the end I have decided to go with the one on my latest meerkat drawing ,