Since I started getting email regularly 20 years ago, I have never sent myself an email covering a meeting 15 days old. One would have difficulty remembering anything clearly over that time span if you didn’t have notes, and you had a lot of meetings as Rice surely did and I have had.
Let’s see the notes.
In my line of work, on rare occasion I have sent email to myself to document something. Sometimes I write the email using handwritten notes that I had taken from the meeting; then the notes are shredded. But this would be done within a day of the meeting; as you say - it is harder to remember 15 days later and one might be tempted to include facts (subsequently known) or “thoughts” that were never discussed at the meeting.
So yes, 15 days after the meeting raises suspicion. One would need to see her work habits and other emails. For example, I would look at whether she wrote other self-emails about conversations that included BHO, how soon they were written after the meeting. Consider also it would be unusual to write an email to oneself when one knew that they would not be part of the next administration . . . perhaps in hours from the actual writing. Why would she still thinking about that meeting 15 days after it occurred and she was going out the door? Finally, Benghazi should come back to “haunt” (impeach) her on this issue - her (lack of) credibility and tendency to lie on official government matters has already been established.