Living with such a perfect autobiographical memory for Julie was blessing and a curse. Her case allowed her to catch the smallest details of the course of events.
From the text, we know that her “abilities” appeared at a young age so it didn’t “fall” on her suddenly. She had chance to adapt to this state of affairs.
Jill can recall her memories which is in my opinion a huge gift. How many times have we dreamed to come back to the memories of our beloved grandfather? When in worse moments we tried to cheer ourselves by remembering holidays by the sea? Jill had very transparent access to it.
As I wrote before, I think it is a gift. But on the other hand it is a curse. Returning to stressful situations for us or just unpleasant situations must be just not nice. Jill, unfortunately, despite her condition, couldn’t refuse these adverse moments. She had to live with them. So in my opinion Jill was both, curse and gifted in her way, from a very young age.