Go ahead and file a report to animal control.
If a 5-6 year old kid on a bike gets mauled tomorrow because the lady wasn't warned...then it's on her.
I have a 3 strikes rule. Pit bull came into my yard once...with my young kids outside. Told them to stay in the pool and I'll work this dog out. Got him out and reported to animal control. Second time he was dragging a logging chain. Again...called animal control. 3rd time I was going to shoot it, but there was a nice bulldog with it. Trapped the pit in back fenced in area and called AC again and had it forcibly removed and taken away. Bulldog was new neighbors and it was released to them.
Last two events I had my pistol with me and any aggressive movement was going to cost that dog his life.