June 17th, 2016 at 11:07pm
As you mentioned that her dad doesn't approve of her sexuality, perhaps (if you want to really create some unsolved turmoil) she and her dad could have a related argument. Then, not long afterwards (perhaps the following day or the same evening), her dad dies or is critically injured (i.e. car crash) and she could suffer from immense guilt. She could blame herself for upsetting her father and causing it to consume him which possibly caused him to lose concentration while driving, for example.
Then the bisexual could be the peace-bringer for her - they could have had a relationship with a man who seems similar to the MC's dad in some way or another and be able to help the MC feel less guilt through relation and understanding. Perhaps it could encourage her to start a pro-LGBT campaign or something, where she faces similar ridicule to that of her father but makes it her aim to remain calm and try to educate people and try to help them to relate and accept.
Or you could take a U-turn from that developing idea and bring in some new important characters - the victim(s) or the family of the victim(s) involved in the same car crash that took her dad's life.
Just some random ideas I thought I'd share. Take from them what you will. Good luck with the story! :-)
Or maybe the bisexual she falls for is perhaps the victim of the car crash or something. I have a hard time working with a bunch of characters. I'm trying to do things gradually.