The best response to the question about the difference between the challenges that Alyssa and Juliet face is:
Alyssa has to decide who she wants to be with, Reid or Austin, while Juliet does not face a similar decision.
This choice reflects the conflict Alyssa experiences in her relationships, while Juliet's challenges lie more in the feud between her family and Romeo's family, as well as the societal obstacles they face.