So you interrupted an extremely stressedother by saying... Your upsetting me ... Why do I imagine that was done in your best middle class voice‽
If you were that upset, why on earth did you say something so daft and PATRONISING?
Round here, you'd have been advised to say .. oi twat, stop doing that to your daughter, you're making it worse.
Then go tell the teacher, and head.
There's obviously 2 issues here ... An extremely stressed child that hates school for whatever reason, and you have aother who is fed up of this daily battle .. probably told by the school, you must make sure she attends or you'll be fined.
The key would have been... Asking if she needed help .. which she did ..Aube take the smallest child, so she had 2 hands on her other child... Thus she wouldn't have reverting to dragging.
Maybe afterwards, asking why her daughter fights daily to go to school and offering a hand, instead of just condemning and running to mumsnet, to seek approval!
Practical help is always better, then just "disapproval". How.do you know the mother hasn't got other issues going on?