Puppies have needle sharp teeth and love to play, play for puppies is jumping, biting, scratching, nipping, chewing things they shouldn't chew etc. This is why people with children need to think very carefully before buying a puppy.
If your friend had bought from a reputable breeder, she would have expert advise on the other end of the phone.
I'm in two minds about this tbh, I don't think anyone should re home easily and vehemently wish people who don't have a clue about dogs would stop buying cute, fluffy puppies but it doesn't sound to me as though your friend is cut out for dog ownership.
A Dalmatian, as already pointed out, will grow to Dalmatian size, that's simple common sense. I don't understand how this dog has gotten too big?
What was your friend expecting a large breed dog to grow into? Plus leaving puppies and children unattended is a massive no no. Even a short bit of research would have taught your friend this.
If you're friend can pull her finger out and get her act together, then by all means she should keep the puppy, it doesn't sound like an act of aggression, most puppies are incapable of aggression, they're babies, innocent and new, they learn mistrust and aggression later in life if they're not properly trained and socialised. Otoh, if, as I suspect, this pup is going to end up in rescue anyway, because he's too big/takes too much time/hasn't magically transformed into the perfect trained dog with little to no effort from the owner etc. then she should do the pup a favour and rehome via a reputable breed rescue now, while the puppy is still young and cute and she should never get another dog.
If she decides she is capable of keeping it, then she should contact and APDT registered trainer to come out and speak to her, bite inhibition is very important for a puppy to learn and if, after puppy classes, your friend still thought it was fine to leave a puppy unattended with children, then she is obviously not getting all she should be from the puppy class, also the trainer will be happy to have a word with DP and reassure him that this was just play and with responsible management won't happen again.
If she gets rid, she should not get another dog and definitely no more puppies.
How sad for the poor puppy and the dd.