She was just petting the dog. Dog bites can easily be avoided. Prevention is the key. When a child is bitten by the family dog, it is usually the child itself who is the instigator. For example, it is often easier to feed the dog while the young child is toddling or crawling around in the dog's feeding area.
Dogs are animals that protect their food.
The Basics of Dog 101 tells us to feed the dog somewhere else - in the crate, or when the child is asleep or in the high chair. Take time to use the dog's water bowl to teach the youngster not to ever touch the dog's dishes. Explain to the children that dogs don't have hands and must use teeth to hold things like toys and cookies. Even the smallest child can usually understand this concept, however many times you have to repeat it. A youngster wildly waving her arms and hands about, with or without a treat, usually waves those arms and hands in front of her face.