I require one.

First it allows me insights into what's going on in her head that I would more likely be aware of if we were together. She often confesses feelings and concerns in it that I would otherwise have totally missed during the conversation, or that she hid from me at the time, and helps me keep her on track... and me on target.

Secondly, recounting her activities and feelings reminds her of and reinforces her submissive nature, which she is in the process of discovering. Sometimes, by the end of a journal entry, I can see she has already resolved her concerns and is in a better state of mind. And I often see the subtle results during our next conversation. Yes... a journal is almost a neccesity.

Third, one of her jobs is to entertain me. The journal is one of the venues she has available to her.