What should I do?????

I do feel comfortable around my boyfriends family but at the same time I don't. His family consists of mostly all women his grandma had 3 girls. They all care about how they look they all wear make up (I hate make up) and they are all curves and about their body. They all recently got their boobs done. His grandma paid for it cause she got that money. But here I am everytime I go to his family gathering I'm slim. I'm an A cup my booty measures to like 34. Small I know. But I just feel insecure around his family because I feel like they think like omg this girl is so skinny she doesn't eat (I'm 5'2 I weigh 100) but dont worry guys I eat a lot. The doctor says I have a fast metabolism so I'm healthy. But still around his family I don't feel as confident. But my boyfriend loves me and my body just the way I am😊