GO VEGAN! It's an awesome lifestyle, but YOU HAVE TO EAT ENOUGH CALORIES. YOU CAN'T BE AFRAID TO SMASH IN THE CALORIES!
I'm a 17 year old boy who is vegan at a boarding school where the vegan options are limited. I am 5'8 and 130 lbs, run around 40-60 mpw, but eat 5000 calories a day (yes I accurately monitor this to make sure I AM EATING ENOUGH. This isn't a Jordan Hasay I eat 5000 calories a day bull shit). I eat a pretty simple diet that focuses on just a few staples. Here is sample of what I might eat in a day:
Breakfast: 30-35 medjool dates: 2000 cal
Lunch: either more fruit like 10 bananas with sugar or some rice and veggetables (I keep it light at lunch because I have practice so it's only like 1000 cal)
Dinner: Feast Time! I'll eat 8-12 cups of white rice (or a lot of potatoes if available) with a bunch of vegetables (lettuce, spinach, carrots, bell peppers, peas, chickpeas, beans, ect.) and Siracha
(like 1800-2300 cals).
It takes no effort/obsessiveness for me to track my food on Cronometer, since I know a bowl at my school holds 4 cups. I just eat until I'm very full, live hard, train hard, be in the top 10% of my class at a competitive prep school, and feel like an energizer bunny! I get all my vitamins and minerals (I supplement b12, but this isn't just a vegan problem!) and get the recommended 1.2-1.4g protein per kg of body weight that is recommended for endurance athletes. I have had numerourous blood tests and everyone has come back PERFECT! The most important macronutrient in CARBOHYDRATES! Your body primarily runs on SUGAR so it's important to get the CARBS and CALORIES in. Sorry if it seems like I am overemphasizing the whole Calorie thing but that is so crucial to being HAPPY, HEALTHY and being able to train/perform. NO RESTRICTION!
To all the people who spew out that vegan food is complicated BS, that is false! Fruit is fast food! It isn't HARD OR EXPENSIVE to make rice, microwave potatoes/veggies, or eat the veggies raw.
Since you are a girl you will most likely need more fats than I do, so add in the avocados, soy, or nut butters! If you need any help just ask!