I had experience with an off leash beach earlier in the year. There were a couple there every day who's dogs ran crazy and annoyed everyone else's dogs without fail. I too yelled at them and told them they needed to learn to control their dogs (they were quite big dogs).

Thing is if it's off leash, she can't tell you off for not having your dogs on leash as it's no illegal. She sounds to me like she struggles to control her dog and likes to blame everyone else.