I'm going to make a wild guess here, but looking at her sig, she has two 7-year-olds and one 4-year-old. The 4yr (if tall enough) would have to sit in a row with Mom or Dad, but the two 7yrs could ride in a row together. (If all 5 ride, it would be the two 7s in a row, the 4yr and one parent in a row, and the other parent as the "odd number.")
Regarding being able to ride alone in a row: As a solo, I've always had a row to myself on BTMRR, but that's a different set-up with a single lap bar for the row. Someone in another thread indicated that they are filling every seat on 7DMT, which makes sense, since it has individual lap bars like EE, AND it's super-popular right now and they need to get as many people as possible through the queue and on the ride.