Journaling a bit, but please review and share thoughts if you could...

This morning I was bringing our S (he's 5) to school. On the way there he became upset and told me that mom was suppose to bring him. I was unaware of this, but changed the subject and talked to him about what was planned for school today. After dropping him off I text the W and asked her if she had told him she would be taking him. She replied that she did or said she "might". I let her know that he was pretty upset about it and that if she said she was going to I felt that she should. She then called and was pretty irate. Saying that plans change and he should get use to it. Also that I don't have to share with her the things he is upset about.

My question is should I have shared it or not? I think it's important to keep his feelings first and share these things when they come up. It was not intended to hurt her feelings or guilt her. But I believe if she says she is going to do something that involves him she should stick to it.