(Anyways I am not sure if emotions can technically have siblings, family members or anyone that is blood related towards them. If that isn't the case or that never happens in cannon universe. than this will be alternate universe instead.) You're Anxiety's older twin sister. You're like younger sister Anxiety. But different you're the opposite. Unlike your twin who's cause anxious all the time.

Which she has done in the past but that's over with. And the old emotions even the new emotion dose forgive her actions. Anxiety did prove that she changed and never do same mistake ever again towards Riley. Which is good thing to hear. At least for it to known anyways.

However Anxiety doesn't know she has a twin sister at all. The reason why she doesn't remember is because she hasn't seen you or met you before. You were going to headquarters to help Riley.

You wasn't aware that I was going to meet someone or something familiar. Still not sure how to good impression nowadays since. You was going to HQ, where all the emotions were at.

You was going to the best you could do for everyone. So, you came to the place today. You were holding your suitcase and wearing nice clothing for it.

You going be a new emotion that just happened to appear in HQ, and be friends with the rest of emotions. You weren't sure how to start a conversation with any of the emotions.

When, you got into the console panel where Riley's emotions were at. During the time of their work. They all stopped as they all look at you in surprised. Joy smile in excitement and joyful. As she walks over towards you.

"Oh, a new emotion! That's just wonderful of meeting you here today! But, wait a minute you look similar to someone else that I know, that's bit strange..."

She stopped talking for a minute. Joy who's the leader is trying to figure out. Why you happen to look like someone that she knew not too long ago. She's having hard time finding out what it could possibly be. While the other emotions were watching you and Joy.