Hi there,
I have two JR's (no kids yet) they are generally good little dogs, BUT they are terrible with cows and sheep, my youngest loves to chase them, so they have to be on a long lead when I take them near sheep to avoid the stress.
Neither of them are that keen on my neices fussing at them, but they are getting used to the little people, both neices love them cos they are smaller than the rest of the dogs they have around them (just prefect size for four and two year olds to boss around!) I have to be honest they can take it for so long and then they have had enough, but so long as your daughter knows to let him have some time on his own it should be ok.
The other thing to note is that although they are small dogs, they do need a lot of exercise and mental stimulation, I can walk my younger dog for 16 miles before she is tired out properly, maybe you could all get on your bikes as a family and go for a ride, that should help to tire him out and then he will be a little more chilled out. JR's do bark, they are quite protective of their space, but if you use positive affirmation and praise and feed him when he does the right things that might help too?
I would advise a look at the breed characteristics for JR's you'll find them online, they are big dogs in a small dog's body and potentially will be your daughter's best buddy and partner in crime, but they do need some firm handling.
Best of luck, I love my two girls and wouldnt be without them :D