Breton Setters

If it is what I think it is, then we came across lots of these in Brittany, as well as the Breton spaniel type too. They are used as hunting dogs because they are easy to train. Most we knew used to live outdoors and they loved swimming.
They seemed friendly enough, never growled, but did bark a lot. I think they like to be busy.

Consult google, you’ll find lots of information. Your OP sounds as though you’re unhappy about the dog arriving in a family with young children
Setters are generally kind dogs, medium sized. They’re trainable. They were bred as working gun dogs so, they need a job.
Is it a pup or a rescue. Are you experienced with dogs but more importantly are your son in law and your daughter