Ask for opinion about a teacher handling matter with a 7 year ol

我家小姑娘妮妮（二年级）最近给自己惹了个麻烦。某日上课老师在折腾smartboard, 可能颇费了些功夫，底下学生等着。妮妮觉得无聊，在小纸条上写 "big o fat,stupid dumb not so smart board". 改天（Wednesday)她想扔掉时被老师发现了。老师问她what is it about? 妮妮觉得犯了错，并不回答 。老师可能因为忙，第二天（Thursday)整天要开会，就跟她说隔天（Friday)要和她talk. 妮妮回家觉得不安，吞吞吐吐，费了老劲才讲了个轮廓。我开始并不以为意，只是告诫她不要随便就写些负面的评价。用在东西上也就罢，可不能拿来说人。老师既然没有向家长汇报，我觉得也不是大事。这样过了一天，晚上妮妮便显得非常焦虑，担心来日的谈话，说不知道如何回答如果老师问为什么这么做。我只好跟她说我会给老师写邮件，告诉老师她已知错。于是写邮件给老师，并加上相信老师的guidance。星期五一天我都没等着老师的回件。晚上妮妮回家说老师已跟她谈过，具体什么我问不太出来。只说老师给她看了我的邮件。等到星期一下午我才收到老师的回邮。She stated that the delayed talk was due to 1) Nini was not open and honest to begin with when she asked about the note and 2) she was out on Thursday. 
"The incident became a bigger issue than it needed to be since she didn’t respond to my question.   Hopefully my talk and your talk will help her realize that if she was just open and honest to begin with- then it wouldn’t have continued into Friday. "  Nini definitely learned a lesson. But I think the teacher was too harsh on a 7 year old. She could handle this matter better instead of delaying the talk. What do you think?