This will prevent Jen from sending you messages, friend request or from viewing your profile. They will not be notified. Comments on discussion boards from them will be hidden by default.
“One had to cram all this stuff into one's mind for the examinations, whether one liked it or not. This coercion had such a deterring effect on me that, after I had passed the final examination, I found the consideration of any scientific problems distasteful to me for an entire year.”
―
Albert Einstein