Growing up Muslim I've dealt with some of the slick stuff people try to do to you when it comes to food.
I'm not accusing the school of intentionally feeding her daughter pork, but I have been in situations where I have accidentally eaten pork because people have failed to inform me there was pork in it ( even when I asked prior to eating ) and they knew damn well there was pork in it.
Yes you should inform your child of what to eat, she's a 2nd grader so she may not be sure of what is in every food.
When I was in the 4th and 5th grade, I had a lunch lady who was generous enough to let me if something had pork in it. But not every lunch lady is so generous.
However, I do think the mother should just send a packed lunch to school to be on the safe side. The mother should be glad her daughter attends a school where packed lunches are allowed because many schools nowadays do not allow lunch from home.
What is unacceptable about this story if it is true is twofold:
1) The report is poorly written and it did not indicate to whom the mother issued a threat of a lawsuit. We are informed that the school district made the reply but no name or position is attached to the reply. Nevertheless, the tone of the letter is indeed "brutal" and unbecoming of an educational institution. It was wrong to write in such a hostile way and I am surprised that the district lawyer would let such a letter be sent to the mother.
2) Regardless of any religious motive the mother might have had, she did provide the school with a doctor's note stating that the child should not be given any pork or its products. Schools must honor medical notes. Consider a child who has an allergy which could prove serious if disregarded by the school. The school district is, without question, leaving itself open to a lawsuit.