Cat found, Sydney

Domestic shorthair, small white and tabby female. Young (9 months?). We call her Syd and she responds to my voice, currently spending most of her time in our garden. She has a healing sore on one shoulder. She is friendly and playful. She is lost rather than feral I think. We are currently feeding her, but have our own, currently rather territorial, cat. Would like to find Syd's owners..