I'm with sarah Stratton above and all the others that say they simply don't beleive it...
Too many inconsistancies for me
There are 2 coffee shops in the area - 1 5 minutes walk away that they OP was in and one "right next to the school" that the OP can't use because of her health issues
However the ONLY shop for food is 2 and a bit streets away down by the river..
Half an hour late isn;t a big deal in their culture hence no-one should have been getting really stressed about it before....but the OP has never ever been late picking up before.
Its in Central London, its in Zone 2, its a housing estate, its a horrible place (with a choice of nice coffee shops)
In the playground, on the streets, in the playground but anyone can access the playground so it might as well have been on the streets....
My DH noticed she had been crying and the teacher just dismissed it - then it becomes that no-one knew what had happened until bedtime...
The OP has ASSUMMED that the "teacher" (Girl paid by the consule to teach the children the language/culture which frankly could be done at home anyway) went to this only food shop in the area that was 2 streets away without any indication from either the teacher or the OP's DD that this was what actually happened...
When any of these inconsistancies are challeneged all we hear from the OP is "but none of this is important, she asked my daughter to lie..." - which language did this happen in - the teacher's native language that your DD has to go to classes to understand, or English, your DD's presumed native language, which isn;t the teacher's native language....whatever language the whole conversation about lunch and "I'm just in the next classroom", it was a non-native language for one of them....
Well OP, if "lying" is such an awful thing in your family, and THAT is what needs to be concentrated on in this story, then I suggest you take the plank out of your own eye (all the inconsistancies above) before attacking the spec in the teachers eye...
or does it not matter if you are lying to us as we aren't children...