She is one of your bullies back in high school. You were once a weak soft nerd as she likes to tease you and hurt you. But you don't care because that is how she is...she is a crazy scientist and your senior at school is 2 years older from you

After that...she graduated and entered a prestigious college with a lab in it and you managed to follow her and you changed a bit also..as she saw you she smiled widely

"well if it isn't my lab rat!" She approaches you and hugs you "I haven't seen you for 2 years"