Report her to the dog warden hun, even if they don't do anything about it right now it's on record.
People just seem to think they have the right to let their dog off lead to do as it chooses.....I've had encounters with people who allow their dogs to run over to my two when on lead then turn their backs cos they have no recall, they soon get verbal abuse because why should my boys be put in a position like that and then made out to be bad dogs.
I walk with other dog owners and we are never ever on phones, like T&C's it's hard to have a conversation flow cos we're all watching our dogs and reacting to things.
Irresponsible dog owners are selfish and ruining the reputations of good owners