With most brakes, the shooter doesn't get nearly as much of the report blast as the person/people next to them, but it IS considerably louder than without a brake.
I'm a huge fan of rifles without recoil, I'm thinking of starting a support group for it in fact. Very satisfying to watch your bullet impact the target. A good pad can help prevent a rifle's recoil from hurting, but only extra weight or a brake can stop the rifle from rebounding (muzzle jump). Weight isn't going to help out a kid, so a brake is probably the best option.
I generally have the kids I take hunting with me wear ear muffs anyway. Little ears are a lot more sensitive than adult ears, and frankly, a kid doesn't know any better, whereas an adult can weigh on their own if they'd want hearing protection (I always plug my ears when my partners shoot, or I wear an ear plug in the ear to the side they are on). Kid's are also the most apt to develop a flinch from muzzle blast, so I usually want to make sure they hear as little as possible. (Not to mention, it passes down a good example to the next generation, stressing the importance of hearing protection while shooting. Wish I would have gotten that lesson, instead of getting a constant ringing in my ears and 60% hearing loss in my left ear for the rest of my life).
Brake it down my friend!