She sits very still. "I can't help you-"
"All right. I love you and I'll figure it out without your help. Bella, is Fëanáro in the right general area?"
"Ugh," Bella says. "If we had oaths on my plane it would have been one. It might have been a different set of rules but it would have been one and I probably would've taken it."
"It is stretching the rules like crazy but she did say a few minutes ago that I 'should' probably tell you everything."
Okay.
And with infinite ginger delicacy she tells him what's going on.
"That shouldn't even count," he says, "oaths are supposed to require intent. But I suppose you dwelled on it afterwards, on what you thought you'd committed, and that'd make it worse -" He shakes his head. "Bella, can you do an action block that is permanent?"
"No," Miriel says.
"She can't say anything else," he says. "Can you?"
"If I can do it at all I can make it permanent but it would be much harder to do without error than the memory veil."
"Similar broad range of side effects I mentioned when I was first warning you that this stuff is potentially hazardous, I'd guess there'd be a bias toward leaving fixed action patterns - getting stuck in loops of behavior and needing help or a context change to break out of them - or obsessive thoughts about the forbidden action, which might happen even if I do pull it off textbook perfect, or making it overbroad so she also couldn't do other, loosely related things..."
"I'm going to go write up a thing for you to sign just for - superstitious peace of mind reasons."
And she goes and gets some paper and writes up as best she can from memory a declaration that Miriel is to be considered incompetent to withhold consent due to prior magical alteration of her will and has two places for Finwë to sign, one as king and one as husband.