A 7 year old peeing the bed or wetting the bed at night is perfectly normal and usually nothing to worry about.
Some kids bladders do not grow as fast like the rest of their body and so they have a smaller bladder and also the bladder muscles can be weaker and when asleep the child cannot hold in the pee.
Then because of those weaker bladder muscles as well as the smaller bladder the child or 7 year old child has a loss of bladder control at night.
Usually a child will grow out of bed wetting by age 8 to 10 years old but some kids may wet the bed until 17 years of age.
My brother wet the bed from birth until age 17 when he finally quit wetting the bed.
He wore diapers for the bed wetting as a kid and adult diapers for the bed wetting as he got older.
My kids wet the bed too and I'm not worried about it.
I have a 6 year old boy who wears Pampers baby dry diapers at night for his bed wetting and he also wears the diapers on long car trips as well because he can fall asleep and wet his pants in the car.
You can use bed wetting medication but it's usually nothing to worry about and having the kid wear a diaper at night or a pull up at night will help keep them dry and comfortable until they grow out of it.