Am I In The Wrong?

So, I wanted to ask y’all abou something that happened to someone I know So this girl who is 9 attend an IB school and is in 5th grade. So basically they have spelling HW and they have to practise these words that are in the HW and then they have a test on it. This girl was sick on the day they gave the HW.

When she was well again and came back to school she went to her teacher and told him she didnt have the spelling HW.The teacher told her that it didnt matter and that it was just spelling.Later that day they ahd a spelling test and because the girl didnt know any of the words she only got 3 correct.So then her teacher started complaining about it to her and said he would mover her down to an easier stage because of this.The girl tried to expain but the teacher didnt listen.Then her mom emailed the teacher but he ignored it.Am I in the wrong for trying to tell the school athorities about this or am I reacting?