It is OK for a 5 year old to wear diapers all the time or anytime.
A lot of 5 year olds today are not potty trained and continue to wear diapers and they will potty train when they are ready and if the 5 year old is never ready to potty train that is okay as well.
A 5 year old or any kid of any age should wear diapers full time or all the time as diapers are much more convenient and more comfortable than underwear.
Size 7 diapers will fit an average sized 5 year old.
A good size 7 diaper that is very absorbent that I would recommend for a 5 year old girl or boy or other kid is a Gentle Steps size 7 diaper which gets very thick when wet.
The Gentle Steps diapers are very absorbent and comfortable and will fit most kids from 5 to 10 years old.
Size 8 diapers are available in Pampers Swaddlers size 8 diapers, Huggies Snug and Dry size 8 diapers, Parents Choice size 8 diapers and Huggies Little Movers size 8 diapers.
