Hello @iehdjfhsks, Unfortunately, in spite our fondest wishes we don’t get to make the decision how tall we’ll become. Your genes decide all of that. How tall are your parents or siblings? Another factor is hormones. Most girls stop growing within a couple of years after they start their monthly periods. You’ve not had that happen yet so you may not have reached your full height.

I found a little article which talks about grown in girls and the importance of hormones in development.
https://www.healthline.com/health/when-do-girls-stop-growing
Not having a period by the age of 14 is a little later than usual. You mentioned that you’re trying to increase your appetite to put on a little weight. Hormone levels are affected by your weight and the amount of fat on your body. If you are underweight, with too little body fat that can impact your menstrual cycle. I was very athletic in school and my low body fat changed my cycle for quite a while.
https://www.verywellhealth.com/changes-in-your-weight-and-missing-your-period-4105209#:~:text=Hormone%20levels%20are%20affected%20by%20your%20weight%20and,fluctuations%20can%20also%20interfere%20with%20your%20menstrual%20cycle.
Have you talked to your mom about your period? Sometimes, getting a late period can run in generations. It might be normal for the women in your family to have this arrive later. If not, you still may want to talk this over with your mom. Have you had a checkup with a doctor recently?