Why do you feel like something is wrong with your daughter's weight? She sounds perfectly normal to me.
Roughly 2% of the population falls beneath the 5th or above the 95% percentile for weight normally.
Rather than encouraging unhealthy habits, resulting in a child who may be thin but still at the same risk for cardiovasvular disease as a fat child, encourage healthy eating habits, and allow her to develop her own eating pattern. She may be a 3 meal a day kid or a grazer. Either is normal!
Also, I am not a fan of carnation instant breakfast or any other meal substitutes, like pediasure, in a child who is developmentally normal. All that stuff is really just whole milk with sugar and vitamins, and, in the case of pediasure, some artifical fat. It is really all just a bunch of processed food that you are giving your child for no real reason. Much healthier would be to promote natural and healthy fats. For example, if she eats rice or pasta, a tablespoon of organic olive or canola oil is a much healthier substitute and she will get 14 grams of fat from that, plus antioxidants. If she eats pancakes, a tablespoon of organic butter will do the same thing (minus antioxidants).
Finally, watch for the amount of juice and milk she drinks, both of which blunt the natural appetites of many toddlers. No more than 4 ounces of pure juice and 16-20 ounces of milk a day. She still needs whole milk, but after the age of 2, 1-2% will be recommended. If her weight concerns you it won't hurt to keep her on whole milk even after two years old.
And one more thing...keeping your kid on a bottle will not promote weight gain, you know. It will not really encourage her to eat more calorie dense foods. You know this! Are you just holding on to it because you are anxious about her weight? No judgements here! I did the same thing, actually, even though I knew better. But in any case, it is to her benefit to at least switch her over to sippy or (oh, heck, why not?) a cup sooner rather than later. The fight you don't want to face today will become a monster of a fight tomorrow. I say, get over your anxieties and get rid of it. Your daughter really does sound like a perfectly happy, healthy, and beautiful child.