To want to? No. To do it? Of course.
But you didn't.
As for your DD, I do not judge her one iota for telling this woman to fuck off. My 2yo DS went missing in a shopping centre. Literally by my side one second, gone the next. I was picking up a prescription in Boots and he was stood holding on to the buggy (which had 5mo DD in it). Then he wasn't. He was nowhere in the shop either.
There is no panic like it. Any rational thought gives way to screaming terror. They have immediately been snatched by a predator on run into the path of a juggernaut.
I ran the length of that shopping centre, screaming at the security guards to lock the doors. Ridiculous, in hindsight, but I was so, so frightened. Suddenly a woman was walking towards me leading a little boy who looked like mine by the hand. I couldn't process that it was him, I was just so hysterical.
Her own toddler had been on the little £1 rides down the other end of shopping centre. When we'd passed earlier, I had told DS I had no change for them (whether this was true, I can't remember). He hadn't seemed unduly bothered, but as soon as my eyes were off him for a second, he'd legged it up there and jumped in alongside this woman's DD freeloader
As he came trotting back he proudly said 'I runned away Mummy!' Little sod. He never did it again, thankfully, because my heart wouldn't have taken it, but I have never forgotten that fear.
So, in that circumstance, someone wouldn't help me because I was young (which I was, in fact, as well as married, mortgaged and paying plenty of tax, because having a baby in your early twenties does not preclude such things), I think I'd be inclined to tell them to fuck off as well.
That being said, I wouldn't waste any more time thinking about the woman. If you have to feel anything about her, feel sorry for her. She can't have had much joy in her life to be so hard-hearted.