Hi there,
Welcome! I'm fairly new here myself, although I've been successfully, if slowly, losing weight and keeping it off for a while now. I definitely agree with Wyllenn -- you can lose weight eating more calories than you are. 1200 is the bare bones minimum a woman should eat without medical supervision if she's totally sedentary.
A good rule of thumb is 8-12x body weight daily in calories to lose weight. Higher end if you're very athletic or if you're under 25 or so, lower end if you're not active or more mature. Your range would be about 2000-2800 now. Then you lower the calories as you lose weight. I don't what your exercise routine is but since you're young the middle (2400) should be a fine place to start, just to try for a couple of weeks. Overly restricting rcauses you to lose healthy muscle tissue instead of fat and reduces the likelihood you'll stay on plan. Plus, if you start at rockbottom calories, where can you go from there as you proceed?
Also, I get the idea by what you said about making sure you get a good dinner that you might be hoarding calories for the evening. Make sure to spread out your calories in meals and snacks throughout the day to keep your appetite in control. This will be easier to do if you eat more calories.
Best of luck to you!