I'm sure Dibaba will better her sister's time, but doubt she will win.
The last time they raced, Dibaba had a hard time hanging on to Ayana, clipping her heels several times, and only leading one lap of the race where she slowed the pace 5 seconds from the previous one. Alana took over from then on and ran the next one 6 seconds faster.
In her 14:14 solo this year Ayana ran splits of 2:54, 2:55, 2:47, 2:50, 2:48, and bettered her previous time by 14 seconds. Her goal was 14:22.
I'm looking forward to this race, more than any of the others.