Yes it's normal for a 10 year old to wet the bed.
Some kids stop wetting the bed at age 4 or 5 years old and some continue to wet the bed until 10 years old to 13 years old and that is normal as well.
Then some kids may continue to wet the bed until age 16 to 17 years old and some may continue wetting the bed until 21 or even for life.
If the 10 year old is healthy overall then the wetting the bed is usually not a bad thing health wise.
Most times the bed wetting is usually caused by a bladder not growing properly.
Most times the bed wetting will resolve on it's own without any issues.
But if you're worried you can have a doctor checkup the 10 year old and do some tests.