You should be drinking 8 cups of water a day for your health. At 5'4" and your weight You do not need to lose weight. You are at the low end for your height as is. If you have any concerns about your weight you need to talk to your doctor.
About 8 cups a day is normal for that weight and height- i talked to my doctor because i wasnt drinking enough water- im about the same height and weight except a little lighter. So drink at least 8 cups a day, i suggest 9 or 10 cups of your trying to loose weight