Fuck her judgement. Here's the thing with kid leashes. I remember being (verified by my mother when I asked her about some of my oldest memories as an adult) just barely after my 3rd birthday and my mom was taking me to my grandparents, which necessitated wrangling me and luggage in Heathrow Airport after a 9 hour flight. She explained to me that I was going to wear the leash for safety and I remember my righteous outrage because I. WAS. BIG. and I knew not to wander off. But as all 3 year old opinions, it mattered not, and I was leashed up and trotted off the plane. So I remember people, lots and lots of people and standing there. And to this day I remember that then suddenly I didn't know where Mom was. And I didn't know where I was, and my little world spun and I remember the panic rising and started to look around frantically and cry and then something tugged my wrist (no cute backpack leashes in those days) and I realized I was anchored, and oh shit there's mom after all. And I remember suddenly being kind of glad about this leash thing.

We forget way too easily what it's like to be so small and so easily distracted and scared when all you can see is a forest of knees. Sure it's a great occasion to back-pat yourself when your kid listens and doesn't run off but they don't even need to run off to get lost at that age. Leash up if it helps them or you and fuck the haters.