I always felt sorry for Jenny. She was treated so shabbily not only by Quentin but also by Judith and Edward.
[spoiler]According to Quentin neither of them accepted her. (Boy I can believe that! And this was long before Jenny's gypsy orgins was discovered). They probably made her feel as welcomed at Collinwood as the plague.
Then Quentin runs out on her with Laura, his brother's wife! Poor Jenny just couldn't handle it and went mad. Did Judith and Edward care one little bit about her welfare? NO!!! They were more worried about what the scandal would do to their precious family name. Beth even said that Edward tried to bribe Jenny to go away (some brother-in-law!) until he found out she was pregnant and insane.
Under the circumstances wouldn't the humane thing to do would be to send Jenny to an asylum in the first place, make sure she got the proper care, treatment and rest, especially since she was gonna have a child? Nope, Judith and Edward had her imprisoned in the tower room! (I am wondering did Jenny have the babies in the tower room?! Now THAT would have been something to see!) Keeping her in confinement I think only further deteriorated her mental state and had Judith and Edward had even at least one iota of compassion for her they would have realized that.[/spoiler]
I think Jenny was Marie Wallace's best role. She was wonderful as Jenny. She really made you feel for her.