Okay, i copied your list. I'm going to knock off any i think are definate no nos for you, and give you some info on the others.
Boxers- Can be dominant and dog-aggressive, but from a good breeder with proper Soc. i think it would work out.
Labs- a little bit more rambunctious and larger than a golden. Okay with kids, but a puppy wouldn't be the best choice here.
Goldens- It might be a little hard to find a good breeder, but definately not impossible. This dog will run agility, be good with children and other dogs, but until it's about two, it's going to be just as much work exercising and training as an australian shepherd. I would definately recommend getting a golden from a rescue.
German Shepherds- i think a well bred german shepherd would be a good choice, but they are big. A large puppy will knock over, step on, and probably injure a child. People may be afraid of them as a breed. I think a german shepherd is an amazing dog, but i definately think a GSD puppy is for a very experienced dog owner.
Border Terrier- i don't recommend terriers for children, although i know border terriers are one of the mellower terriers. This doesn't seem like the right dog for you, because of the size and your child.
Australian Shepherd - They are VERY energetic and need stimulation, but not as hyper as say, a border collie. As with any herding breed, can herd children, but can easily be trained not too. An Aussie who gets enough exercise makes an AMAZING pet. Awesome agility dogs. I just don't know how much time you have for training and exercise.
Brittany- Brittanys are a medium sized dog, not the large size you're looking for, but they are EXCELLENT dogs. Incredibly easy to train, good around kids, energetic but not wild, etc. I know one from my brief experience with an agility class, and this dog was really, really great.
Collie-smooth and rough collies have a VERY VERY similar temperment. They're eager to please, energetic but not overly hyper, trainable, and appropriate agility dogs. However, any herding breed can attempt to herd children, but i think if raised with kids and also given an outlet (agility) they would be a good choice.
Keeshond- i don't know too many keeshonds. I don't think they're known for their obedience. I won't immediately say bad choice but i'd do a lot more research if i were you.
Bernese Mountain Dog- probably a bad choice. They are VERY gentle with children when older, but a 100lb puppy can EASILY hurt a child. You'd have trouble running agility as well. They have a lot of coat, don't do well in heat, but are very loyal and very obedient and eager to please.
Boston Terrier-Small, yes. But as long as you're daughter is gentle (which she probably is from living with a dog already), they'd be a good choice. Very trainable, good at agility, granted you won't see too many BT agility champions, but there is no reason why you can't run one for fun.
I would chose between a Brittany Spaniel and a Golden Retriever if i were you, or maybe a Boston Terrier if you're willing to compromise on size.
