I have the same problem. After I told Mrs. Winton her brother was dead and I had sex with the quest stayed in my journal but when I click on it th journal page is empty. I have noticed that I could raise Mrs. Winton affection through sex. Am I supposed to reach a certain treshold ? It could have been nice to have an indication if that is the case.
I am currently on version 0.8.1.2b.
It is such a great game, I absolutey love it !
EDIT : I have just found out that I have Joseph Winton's journal in my library (book icon in the lower left corner. I clicked on it and my journal updated !