She did NOT break the dress code. It says nothing about dress pants, it only mentions jeans and length of dresses.
I read their dress code after I posted my comment but it does say “semi-formal dresses” so it seems they did not want slacks or jumpsuits.
If I was in charge of dress code I would not have an issue with slacks or jumpsuits since many are considered semi-formal. I would be far more worried about the lack of fabric some dresses have now.
It does seem she violated dress code. If she had a question about it, she should have asked ahead of time.
Read the rules at #13. Girls were supposed to wear dresses, with no other options.
"Semi-Formal Dresses for young ladies."
I can explain it to you, but I can't understand it for you.