Its not a nice feeling having a dog being aggressive to you even as an adult, having been bitten a couple of times from dogs on the loose I can understand the concern here.

When there is kids concerned I would deal with this urgently as the last thing you want is a mauled kid after a problem or potential for one has been identified. The 1st port of call must be the owner regardless of how safe she thinks it is the animal is showing hostility which is a potential for someone being bitten and a kid is far more likely to be bitten on the face than an adult.

If you dont get any satisfaction from the owner which is a very real possibility as I have encountered the "oh it wont hurt you" owner types before, then you need to either get the police or animal control involved.

Its pretty ridiculous if you cant let your kid out to ride a bike without worrying about a dog attacking them something needs to be done soon.

I have 2 kids the youngest being 3 next month and if I am out with him and someone has a dog thats not on the lead I pick him up and in no uncertain terms tell the owner to get a lead on it.

I had to beat a German Shepard almost to death once to stop it from savaging a little boy although this was a gaurd dog that escaped from its pen, dogs (violent ones ) can inflict serious long term damage which can leave permenent scars etc.

Dogs more often than not that are aggressive have not had a proper upbringing or training, the owner doesn't bother with them or train them accordingly. Dogs that are looked after and trained properly can be the most loyal gentle animals on earth.

Its a shame in this case the dog seems to have had no direction or training as a pup and ultimately the owner will prove to the dogs demise.