Suggestions for gaining weight? (female)?

One, you should be happy with your own body first. If you don't mind being a little more 'full-figured', then ok. To help gain weight, make sure you're still getting all of your food groups in. Don't eat the bad food just to gain weight, you'll gain fat weight, which is not good for your health or looks. Don't increase your fats a lot, but try increasing your protein and carbohydrates. There are also some healthier weight gain powders in health food stores that you can try. And nothing is wrong with being active, it's healthy for you.