At least make the introductions slow until the dog knows how to behave around a child. However, even then a dog should not be left alone around a child.
They say that you should also have a place where the dog can go, but the child can’t, so the dog has an escape route to protect itself.
My sister’s dog was smart. Whenever I brought my kids over, he went right behind the sofa and stayed there. He knew there was no upside.