I am so sorry your kitty is missing. Try these tips. Perhaps one of them will help bring her home.
If you have not already done so, put something with an odor that Pebbles would recognize outside your door. It could be her food dish, cat bed, carrier, favorite blanket, or even something that you have worn recently but have not yet laundered. Cats who get out rarely go far and they have a keen sense of smell so a familiar scent can help lead them home. Check for Pebbles often, especially in the morning and around dusk when cats are the most active.
Use a strong flashlight to search hiding places in the area such as under porches, under bushes, behind in between garbage containers and recycling bins. Go back and check the same spots at different times of day. Pebbles may not be in any of them when you first look, but she could show up in one of them later.
Ask neighbors to look for Pebbles in their garages. She might seek shelter in an open one, slip in unnoticed, and be trapped there when the door is shut. Give neighbors your contact number. That way if they do see her they can keep her closed safely inside and call you immediately to come and get her.
Contact animal shelters and rescue organizations to see if anybody has brought in a cat that looks like Pebbles. Somebody could find her, not know how to locate her family, and think that the best thing they can do is surrender her to a humane facility. Leave your number with all of the places that you reach. Ask them to call you if anybody should bring in a cat that resembles yours.
Post flyers with Pebbles’s photo and your contact info throughout the neighborhood, asking anybody who sees her to call you immediately. Include any information (such as if and how she likes to be petted or her favorite treats) that might help a person who sees her keep her in the same area until you can get there.
Be sure to call Pebbles by name whenever you are outside looking for her or even if you just step out to do something like get your mail or take out the garbage. She might be nearby and able to hear you. Don’t yell since loud voices can scare a cat. Use the same tone of voice that you use when you call her inside the house. That helped us find our lost cat after she had been missing for three days. She finally meowed in response to her name, but even though we could hear her we could not see where she was. We followed the sound and discovered her hiding in a sheltered alcove by a neighbor’s garage – a place we had already checked several times.
If nothing else works, you could try setting up a humane trap on your porch or by your door in case Pebbles is visiting in the middle of the night when you aren’t awake to see her. (I believe that some shelters will let you borrow a humane trap for a small deposit fee. Ask them about this when you call to see if anybody has brought Girl to their facility.)
Good luck! And don’t give up hope. Cats have been known to return after days, weeks, even months and sometimes years. But I hope that Pebbles is back home very, very soon.