Your normal body weight for height is 144 to 176 pounds. You need to gain about 20 pounds of muscle and this will take eating more food and weight training. If you wanted to compete in sports, your weight goal could be even higher depending on the sport yet still maintain a 9% body fat.
Your eating plan should contain enough calories to gain about 1 pound per week. I used Healthy Body Calculator® to calculate your basal metabolic calories at 1574 plus very light activity (mostly sitting and standing) at an additional 458 calories for a total of over 2029 calories per day. (This does not include calories burned during exercise.) To the 2029 calories, you need to add an additional 500 calories per day to gain 1 pound per week. The calorie goal you should consume per day is around 2500 to achieve your weight goal. You will need to adjust the calories upward as you gain weight as mostly lean body tissue, especially muscle, which needs calories to function. The more you weigh, the more calories your body burns so the more calories you need to eat to continue gaining or at least maintaining your higher weight.
The foods you eat should be planned using My Plate. Look for suggestions on what foods, number, and size of servings. Or you could use my HELP Healthy Eating For Life Plan® to create a custom healthy eating plan that you can use to gain weight as well as maintain your higher healthier weight.
The other component of your plan to gain weight should be a weight training program to support your goal of gaining muscle weight, not body fat. Talk to an exercise physiologist or call the gym/health club where you currently exercise to work with a certified personal trainer to achieve your goal of maintaining 9% body fat. It should include aerobic exercise that breaks a sweat and weight lifting to increase muscle mass.