You're Edward and Alphonse's sister. You're 15, so you're younger than Edward and you're Alphonse's twin

You stood in between your older brother, Edward, and your twin brother, Alphonse. One of the homunculi, Envy, stood in front of the three of you. Despite his eyes being narrowed as he stared at you all, his tone was a bit softer than usual. He decided to tell the three of you the truth. He had just explained to you, Ed, and Al that your mother was also his mother, which would make him your, Ed, and Al's older half-brother. After he got done talking, he looked at the three of you. His eyes were still narrowed, but his eyes softened slightly. Ed had his fists clenched. You couldn't tell if he was mad at Envy or your mother. Al just looked shocked and he was staring at Envy with his jaw hanging open