Stray Calico Cat....Loving Home Needed

We have had a calico cat around our house the last few days. The poor thing is so skinny! We've been feeding her and can't bear to see her so sickly. We'd keep her, but we already have two cats in the house and they hiss at each other....not good. I don't wanna call the animal shelter, I will as a last resort. But, I've been calling her "Pheobe." I'm a Friends addict, and Pheobe has a song called "Smelly Cat" and that is where the name came from. Anyways, from what I can tell, she doesn't look quite full grown. She is very sweet and loves attention. We think she was someones cat and then they dumped her off in our neighborhood because she is not skiddish around people. She has been very friendly, I just feel bad for poor Phebes...So if you or if you know of anyone who is looking for a pet....please let me know. I will be taking her to the shelter in the next couple of days if I don't get a response. Thanks!