Just to note: I think you've a solid argument for why this wouldn't hold up in court. Everything below is just about what I believe/know and why I think what she did was unethical. It changes nothing, and just exists for my own sake (as I feel like I need to assert and validate myself after I've met a fair bit of scepticism and hostility here).
I'm sorry but this is complete nonsense. You don't have a full account of your mother's incomings and outgoings over the last 23 years.
That's true, you're right to call me out for that. I'm somewhat confident in my own estimates and judgement - based on how she spent and behaved while she raised me - but I have to acknowledge that doesn't meet the burden of proof.
You don't know how much she earnt, what she spent and what she saved.
I know her annual earnings, as she was happy to let me see her payslips (which didn't vary much from month-to-month). But you're right as to outgoings and savings, I don't know anything about that other than my own estimates.
The fact that she apparently had some savings (or who knows, an inheritance, lottery win, whatever)
I know she never had a surprise windfall. So she had to have an alternative source of income to fund her recent investments, which corresponds almost 1:1 to the amount she would have had from child maintenance. But yeah, I'd need an audit of her accounts for the past 20 years to justify this.
after you reached adulthood is not suspicious or unethical. Should single parents never save money?
The general principle is fair. But I'm not debating the general principle.
However, the fact she a) lied about not receiving child maintenance in the first place, b) that, if my suspicions are correct, much of the money was not used for my own benefit (she often told me that we had no money whatsoever when I was young, and used that fact to justify some acts of abuse and control).
Should single parents save money they received to improve the quality of life of their child? Especially if there is longstanding deception regarding the existence of the money, and that money - as I believe - was not used to improve the quality of life of the child while the child was under the parent's care.
Maybe she was saving it for you but changed her mind after you assaulted her and moved out (note: I also sent her a letter disowning her as a parent), as you detail in your other posts.
As I said, I believe she was intending to buy me a car/insurance, as she wanted me to be on call for her from wherever in the country. I don't believe she had good faith intentions for that, but I suppose it doesn't matter in the law's eyes.