I believe the answer is man vs. society.
Margot is having trouble fitting in, she is what you'd call the man, and the people who ridicule her is what you'd call society.
It's not man vs. man because the others are not specified, it's not man vs. nature because there is no implication that there are natural forces in the works, and it's not man vs. himself because Margot isn't causing problems with herself, it's the others.
If this is incorrect, please, don't refrain to tell me. Thank you.