Am I a healthy weight?

Im a 16 year old girl im 5 foot 2, i weigh about a hundred. Sometimes i go to 102. Most of my friends are like 120's and my nanny says i should be at least 110. She yells at my parents for me to eat more but i dont want to get fat. I feel like my ass makes my thighs so wide. Ik im skinny but i compare myself to skinnier legs and say i want those. I compare myself to my boyfriend especially. He's like 90 pounds and he's 17. Ik thats not healthy but its skinnier! I feel so stupid talking like this, i dont want to develop an eating disorder because my friends mother said she loves me and says its really easy to go down that road. But i want to be less than 100, and idk if thats normal. My doctor asks if I've been exercising more, i go for runs with my friend and work out with her sometimes. Idk what to do i want to be healthy and skinnier. Like stick skinny, my bf says i have sexy curves but curves just means youre fat.