Jenna is not innocent but she did not deserve to be treated like that. She will certainly be perfect for any revenge if it depends on Rich.
In the last update it says that she went crazy or died, however I think she is planning something.
Regarding Jenna, the author didn't specify what happened to her (unless I missed something). The update said
"Jenna didn't come back to school after the dance. In fact, we didn't see her again the rest of the year."
On the next text box it said
"
Oh, all the usual rumors. She'd moved. She'd had a nervous breakdown. She'd committed suicide."
On the following text box it said
"But
nobody knew anything. Not that I cared. Made it easier for me not to have to deal with her."
Underscoring added by me.
Very respectfully,
fleet