While we do use Ciprofloxacin in dogs we don't use it nearly as much as the other antibiotics in the fluoroquinolone antibiotic family because it isn't digested and absorbed in as reliable a fashion or rate as others in this family.
The typical dose of Ciprofloxacin in dogs is 10 to 12 mg per pound per day (20 to 25 mg/kg per day) orally.
If Kiki is 13 pounds then a normal dose would be 130mgs to 156mgs. She took 1,000mgs (two 500mg tablets), so that's a pretty hefty dose (6-8X). The good news is that in young adult, otherwise healthy dogs a one time overdose is unlikely to be a problem.
Normal side effects seen with this medication can be nausea and diarrhea.
So you have the option of inducing vomiting and avoiding diarrhea, or taking a wait and see approach and treating the diarrhea with fasting and a bland diet should it occur.
You can give her 1 tablespoon of 3% hydrogen peroxide soaked up with bread chunks, or mixed with ice cream or a little food
Then take her outside and run her around to get the peroxide bubbling so she vomits.
If no vomiting in 10 minutes repeat the peroxide dose once.
If she vomits and seems to clear her stomach and be done I would check to see if the pills are present.
Once she clears her stomach to try and settle her stomach today you can give either:
1) Pepcid-ac (famotidine) at one half of a 10mg tablet per 10 to 20 pounds of body weight every 12 hours.
2) Prilosec (omeprazole) at one half of a 10mg tablet per 10 to 20 pounds of body weight every 24 hours.
These will reduce stomach acid and should help settle her stomach.
Then feed a homemade diet of 1/3 boiled, lean hamburger or boiled, white, skinless chicken, all fats and juices drained off the meat, and 2/3 white rice.
Or you can skip inducing vomiting and just feed the bland diet I wrote about above and see how she comes along.