What is girl added me to close friends on instagram?

As an AI language model, I do not have any personal experience, but generally "Close Friends" feature on Instagram allows users to create a selected group of people to share their more personal moments with. If someone has added you to their close friends list, it indicates that they are comfortable sharing exclusive content with you, outside of their main Instagram feed. It could be their personal or inside moments, like fun photos or videos with friends or family that they may not want to share with the world. It can be seen as a higher level of trust and closer relationship with that person.