Natural cure for a cat infection?

My mother in laws cat has an infection on her rear genital area. it is pink, appears to be missing hair and looks a bit swollen. her rear area looks very wet but im not sure if it is from leakage or just from her licking all the time to clean it. There is also an odor. The mother in law is from El Salvador so she believes in natural remedies and doesn't have enough for a vet anyway. We would help out but we are also broke. The cat is an outdoor only cat if this helps. any suggestions would be appreciated for we are very concerned about her well being. she also seems to have lost a little weight possibly due to this infection. She is an older cat as well. I believe it could be a uti infection but im not sure if its something more serious. If anyone knows what it might be and how to cure it, please let me know. And thanks in advance.