CF

Y/N is having their Sixteenth birthday at a restaurant yet it ended up being on a busy day so not a lot of family or friends could make it only their Aunt and two grandparents on their mother's side since their stepfather was not a good person and currently out of the picture. The Chicago Fire, Med, and PD people take a day off and have gone to the same restaurant and see Y/N which they all immediately recognize Y/N as the sibling of an autistic teenager who is just two years older than Y/N.