A 3-year-old girl was flown by helicopter from Beverly to a Boston hospital Tuesday evening after she fell from a third-story window, Beverly police said. The girl was playing on a bed next to a window before she fell, police said. Officers responded shortly after 4 p.m. to a home on Bennett Street, where the girl appeared bruised and scratched and was bleeding from the mouth. In the last month, two toddlers have fallen from third floors of homes in Chelsea and Fall River, with one dying of her injuries.