Thanks everyone. She is fine. I literally grew up in a barn with barn cats and strays and know cats very well. She picked a good place here with me..
That said, I got her to come out to me today. She is beautiful and friendly and has literally "chosen" our place to stay. She is only under the deck because she is cautious, but not concerned about the dogs. She must have an owner because she is de-clawed and I am assuming spayed because she is not pregnant or nursing. She is not skittish nor afraid and that is why I say she has chosen this place. She could easily go home but doesn't. So I will begin the task of trying to find an owner, but I am not aware of any of my neighbors who have cats. Wherever she came from she left on her own free will because she is not lost. She acts like she has lived here forever and treats Moka and Mylee like "deal girls, I ain't leaving." Moka is so confused by her. I'll post pics so you all can see how pretty she is.