Um... I don't want to get slammed here, but as babies get older, they start to hold their urine for longer periods of time. Maybe not at 11 months, but certainly by 18-20 months you DON'T have to change them as often. Maybe her boy is early at learning to hold it? i know with my youngest, for the last year he was in diapers, I'd only change him 3-4 times a day because that's all he NEEDED. Of course, he was soaked through in the morning, but during the day he seemed to hold it a lot. Just a different POV. I absolutely do NOT advocate leaving a baby in any type of diaper for very long after they've wet, but every baby's different, and some really don't need that many changes. Just sayin'
That is true for our 23 month old. He will go for hours without peeing and then flood. But we still check or change him very often because we are working on using the potty, so we will have some naked time, too.