My daughter is having a ruff year..?

She's a freshmen with a Jr boyfriend. There always together non-stop. She has two brothers (16 and 19). Wherever they go, she's right there next to them. She always says how her life can't get better but I no my divorced killed her inside. Her father's birthday is friday and he's going to Miami. She just found out today and cried. He came over today to eat his "birthday dinner" and she wouldnt even come down to see him. She's sleeping at her boyfriend's house tonight because she doesn't want anything to do with this family anymore. Who knew it would effect her that hes going away this weekend! She lives with me anyways and its not like she visits him on the weekend that much. I fell like i need to do something.. Advice