Earlier quoted context omitted.
If it weren’t her, it’d be another one. There are whole swaths of the populace convinced any child out alone is in mortal danger. They’ll post to the neighborhood Facebook group in panic if they see a child walking to the convenience store unattended.
The funny thing about this is that it's all about reinforcement and standing up for what you believe in. If more parents reported ridiculous busybodies like this woman for harassment, rather than caving in and changing their parenting style, then more potential busybodies would be on notice that their busybody behavior won't be tolerated by the community.
The problem is that the busybodies are usually well-meaning neighbors, trying to protect your kid from what they think is mortal danger. So throwing a fit about it is not a good look, if you care about getting along with your neighbors. The stakes are also very high: if someone gets mad enough, they might well report you to CPS, which is terrifying, especially when local laws in many places in fact allow CPS to decide that you were in fact neglectful. A more effective course of action is to work toward getting your state to pass laws protecting children’s independence.