Lost in Morningside

We have had this wee cat living in our garden for the past couple of weeks. After some prompting with some tasty morsels I am now able to stroke her. She is quite young and so affectionate and very hungry cleaning the bowls of food we put down. Anyway we would love to adopt her but our two cats growl and spit at her so not sure what to do. I may put some posters up and see what response I get.