Last year I worked part time for a special needs school.
I helped change the diapers of special needs students from Kindergarten age to around 8 years of age.
For the Kindergarten age kids some wore Pampers Cruisers size 7 diapers which did a great job at holding in the pee and even poop.
Some of those Kindergarten age kids were skinny enough to fit easily into size 6 diapers or size 7 diapers.
However the older kids would sometimes need Youth Diapers such as Attends Youth Diapers or other brands of Youth Diapers.
For some kids their insurance paid for Youth sized diapers so the brands could vary.
Some of the skinny 8 year old boys that were special needs or incontinent would wear a size 7 Pampers Cruisers or Size 6 Pampers Baby Dry.
I remember one 8 year old boy who was urinary incontinent wore the Dollar General Gentle Steps size 7 diapers.
They worked really great and were very comparable and sometimes even better than Pampers and they are cheaper too.
Some kids can fit into toddler diapers even at age 5 to 8 years old because they are skinny enough although some kids of the same age may be built a big bigger and need Youth Sized diapers or Pull Ups.