So there's no problem that a young child has been taught that the people in authority in her life ask her to keep secrets and lies from her mother.
So a 'teacher' can tell her to lie to her mother... About physical contact and intimate behaviours.
And that a 'teacher' can make personal and rude comments about her mother on school grounds.
What the father and TA are doing may not be abuse or merit social services intervention, but as has been discussed many times on here, SS intervention thresholds are notoriously high, and I'm not sure that this should become the guide to good parenting and professional behaviour.
What these two adults are doing is putting the child in a vulnerable position which leaves her open to other adults who push boundaries and ask her to keep secrets.
This is incredibly irresponsible and I would be shocked to find a school that stands by and watches members of staff behave in a way that will be ignoring their basic safeguarding standards and values, and leave a child vulnerable.
I would suggest speaking to the head teacher to keep them informed vs lodging a formal complaint. I'd be up front about the difficulty in raising concerns as the 'wronged wife', and how it would be easy to discredit your concerns as trouble making, yet, there are concerns and you cannot pretend what's happening is ok. I would situate the discussion firmly in the area of two professionals in a position of authority, and the blurred boundaries, teaching the child to keep secrets and the consequences of teaching a child these things are ok.
I think the best outcome would be if the head teacher could talk to the TA and remind her of her professional obligations and moral code.
- And that being seen to blur private and professional boundaries is at best unprofessional, and at worse leaving a child confused and vulnerable.
- And the secret keeping is incredibly irresponsible and although happened off school property, it's still teaching a child that keeping secrets from their mum is fine when an adult in authority demands they do so. It sounds like the father did the actual asking the child to keep the bed arrangements secret, but the TA was present, and gave tacit approval that secret keeping was fine and she wanted this to happen as the secret was about her sleeping with the child.
... And then the child is being taught by other teachers it's never find to keep a secret and if an adult ever asks you to you need to tell another adult immediately. (I really hope it's another member of staff and this TA isn't in the class room 'teaching' about child safety - can you imagine the awfulness if not?)
So what does she expect to happen next with this child? What does she want to happen because of her behaviour?
- does she want the child to learn that there are 'special exceptions' to the no secrets thing? Like, secrets are fine if the adults tells her it's fine? Or secrets are fine of it's about being in bed together?
- Alternatively, does the TA want the child to inform on her to another adult in authority? And then deal with the consequences of that?
- Or is it ok to discredit other teaching around personal and social education? When the child realises that what the school teaches about these things isn't what happens in real life? Where does that leave the child?
None of those are good outcomes are they?
And surely an adult who presumably has children's best interests at heart will see they need to modify their behaviour.
Or if that's too worthy a motivation, surely they'd be motivated by the potential for putting their own reputation in jeopardy, so maybe, not doing that would be a good thing?
Anyway, I hope you get it sorted without the extremes that have shown themselves on here. Good luck.