I had a similar experience when my little girl, (okay not so little now she's 11), was a toddler.
She would run off the minute she thought you weren't looking, and would refuse to sit in a pram. 'I has legs, I walkies' she would tell me.
Eventually I had to buy one of those toddler harnesses. I was always so stressed when I went shopping, I kept imagining her running off and being hit by a car!

An older mother, her 2 kids then teenagers by the look of them, came up to me and tried telling how unfair it is to my LG to have her on a leash! And that if I couldn't be responsible enough to look after her properly I shouldn't have had kids at all....
Really! I just gaped at her with my mouth hanging open like a fish!

I had no idea what to say.
It bothered me a little bit, still being very young then. But eventually I decided I'd rather know my LG is safe and can't run under a car, than worry about other people's opinions of a toddler harnass!