The 36-year-old posted messages from parents asking for birthday present donation money, labelling them 'bonkers'.
Following the Instagram posts, the angered mothers slammed Myleene, and even the headmistress of the £5,000-a-term school got involved.
But Classic FM presenter Myleene doesn't care. Speaking to Fabulous magazine before she shared the emails, she said: "I have to show you these emails. I'm going to Instagram it later… I changed the names."
It seems Myleene, who is mum to daughters Ava, seven, and three-year-old Hero, knew the emails would cause some upset, but added: "This is why I keep getting myself in trouble. I can't keep my mouth shut.
"But that's who I am. I want my children to receive yo-yos, not Kindles. Being happy is not about stuff."
In the email, the mother of one of Ava's friends asked for donations of 'around £10'. Myleene posted her sarcastic reply, claiming Ava wanted a unicorn for her birthday, informing the parents 'donations' could be made at 'www.getwhatyougiveandendthismadness.com'.
Writing in a newsletter to all parents, the headmistress slammed Myleene. She said: "If you can't tweet anything nice, don't tweet anything at all."
Unsurprisingly former Hear'Say singer Myleene was confronted at the school gates following the shaming, and some parents accused her of using the emails to gain publicity.