missing cat found in Hayes valley?

found this cute kitty in my backyard over the past few days. No collar but looks groomed and is affectionate with humans. I can't tell if she belongs to one of my neighbors, but she's been hanging out with me all day and doesn't want to leave. Posting on nextdoor and here to see if anyone is missing their cat. How soon should I take her to SF SPCA to see if she is chipped?