Good questions. I don’t understand it either. A lot of the women in Hollywood are rabidly pro abortion, so that could be the reason that Jennifer Lawrence and others hate Trump.
There are 2 reasons for JL’s behavior (along with other ‘popular’ movie stars).
1. They are immature and ignorant. They don’t have time to learn for themselves, and depend upon the attitudes of their peers.
2. Their Talent Agent instructs them on what to do and say so as to keep them in the ‘limelight’. These press agents ‘sell’ their ability to manipulate various stars to the politicians and media.