^OP the first time she was warned to step off the path she was hellbent on going down.
These particular children are very familiar with being raised by their father, given that he already had them more than 50% of the time when she decided to pursue maintenance from him. Despite this, he was happy for her to claim both sets of child benefit and give her £300 a month entirely voluntarily (this apparently doesn’t count as ‘compensation’ though).
The CMS gave her advice based on the information she gave them. This isn’t a case of bad advice, but of bad information. When everything started to blow up in her face she was repeatedly told to stop, or at the very least speak to a solicitor. She did neither.
OP’s kids are teenagers, and were well aware that something was going on given the complete breakdown of what was an amicable co-parenting relationship. Their father decided to be honest with them as to the reason why (tbh I’m not convinced that OP wasn’t making barbed comments about their father, as she saw it, failing to financially support her them). It’s not like he would even need to spin it in his favor for them to form a negative opinion of OP’s actions/OP, given that people have done that on here with OP trying to spin it in her favor. He chose not to lie to, or hide information from, them in order to protect their mother’s reputation. He hasn’t alienated them from her, she has.
OP’s injuries are entirely self inflicted. Based on her unwillingness to take responsibility for her own actions and the result of them, she will undoubtedly continue to inflict them going forward.