Depending on your body type, anywhere from 110-140 would be OK.
You lose weight by burning more calories than you take in, so start keeping a food journal, and eating healthier. You DO need to exercise as well, even if it's just taking a walk in the evenings,or taking the stairs instead of the elevator...anything will help.
For a 5'2" female with a light activity level (you don't mention your age...I'll assume you're about 18) you need 2215 calories per day to maintain your current weight. To lose 1 pound per week (the most most doctors reccomend you lose per week is 1-2 pounds, unless you are on a specific weight lose plan drawn up by a physician and dietician) you need to cut your calories per day to about 1715. Of these, about 1500 calories are needed to meet your body's basic energy needs. Track what you eat, but DO NOT compensate for not exercising by eating less than you need to. It's NOT healthy and it will make you feel BAD. If your body does not get all the fuel it needs, it will think it is starving and will go into survival mode, storing more fat. Plus, you'll be tired and lethargic and generally grumpy. And hungry!
Don't go nuts. Eat when you're hungry, but don't overeat. The goal is to not be hungry anymore, not to be FULL. Drink lots of water...at least 8 glasses per day. If you drink sodas, stop. Even the diet ones, although they contain no calories, will make you retain water and should be consumed sparingly. If you drink alcohol, cut down or quit entirely. One shot of liquor has 100 calories and absolutely NO nutritional value. Not really worth it.
Exercise as much as you can...this doesn't mean you have to run 5 miles a day or join a gym (although that would speed your results), but walking instead of driving or taking the stairs instead of the elevator are two easy ways of getting in your exercise. GOOD LUCK!