Explanation below:

• Jane suffered for many years due to bullying and Marissa being an ex-bully rubbed her the wrong way. After all, once a bully always a bully right?

• Marissa was low-key creeped out by Jane, at first she tried to set aside her opinions but as Jane stayed closed off to only her while opening up to everyone else, she grew resentful. Isn't it a bit hypocritical of her to judge Mari based off of her past? Especially considering the reason she was bullied in the first place was because of her appearance.