Yea I was also surprised but this is what I think. She was an orphan in her past life and from the glimpse we got in the previous chapters the dad seemed like to not like her. In this life she sees that her dad cares about her and that everyone dotes on her so she decided to abandon her original plan to escape from sect heir and even if he revolts she will stay with her dad. She cares about the sect heir but she also loves her dad. What she feels for the sect heir right now is two things one is pity because of what her dad then and also a little bit of a crush due to her previous life. Not sure if this helps but this is my perception of it all for now.
Lol that monk is definitely sus. And I'm very confused about MC's feelings towards her father. How does she love him while knowing he murdered the sect heir's parents?