I think Cote D'Azur's suggestion is a good one up to a point but does Hoover really want to keep her DH ??
Could any mother forgive such a massive betrayal of trust - one which involved a painful, and potentially dangerous, assault upon a very young child ?
We can't speak for Hoover until she comes back and says what she's decided to do - and quite obviously, right now, she must be reeling with everything that's happened - but even if Hoover succeeded in preventing any further contact between MIL & her children, would she ever really be able to trust her DH again ?
Remember - he shrugged this off. He told Hoover to take the earrings out if she was "that bothered". He has shown no remorse, made no apology, and doesn't seem shocked by what his mother did. He could be kept in line so far as his mother is concerned with the threat of his prosecution hanging over him ..... but I wonder how long that will keep him in his place ? What happens a year or so down the line when his mother starts pressuring him to see her grandchildren ? Would Hoover be able to trust that there would be no sneaky visits when her back is turned ? Would the threat of police action lose its power after a time ..... when DH assumes it would have "blown over" by then ? Going forward, would Hoover really be able to keep her kids glued to her side forever more ? What if she wants a couple of hours to herself - how would she feel about leaving the kids alone with DH ?
This isn't an argument about, say, MIL feeding the kids fruit shoots against Hoover's wishes ..... to do what she did she must have been totally determined to do what SHE wanted to do, regardless of her DIL's thoughts on the matter (which had been made very clear to her already). Someone as focussed as that won't listen to reason and cannot be trusted at all. And obviously, DH has deferred to his mother, thus indicating that he places her way above anyone else in the family pecking order. If he was prepared to do that ..... and he MUST have known that Hoover would be devastated ..... then you have a man who won't be kept "down" for long, regardless of any threats.
I think MIL should have a restraining order against her for sure. And, I'm sorry to say, that I couldn't remain with someone I couldn't trust and depend upon 100% to protect my children ....... and would have to split. I'd also want supervised access between my ex and the children thereafter, which I know is an awful thing and unnatural etc, etc, but the alternative would be a very high risk of them being exposed to contact with MIL and her bloody earrings. With their outrageous behaviour so far, I have a nasty gut feeling that both MIL and DH wouldn't necessarily be deterred by legal action anyway.
I feel so so sorry for you Hoover.