Demand:
an insistent and peremptory request, made as if by right
ask authoritatively or brusquely.
Can you tell me? is a question. Tell me everything is a demand. Nothing else to say on that, really.
And yes she did volunteer, after lying and telling Geralt she was the love of his life. Seems kind of sketchy for her to only volunteer to help after he starts piecing stuff together. Triss told her own edited version until they had a long conversation about the whole thing and Geralt insisted on knowing everything, even the stuff she doesn't want to tell him. Still not sure what is in question here.
I'm confident I know what demand means which is also why I am confident, it didn't happen.
don't remember much of her lines in Witcher 1 wouldn't be at all surprised she flatout lied and told him she was "the love of her life" but thats not what I remember from the game at all, I do remember she implying there were romantic feelings between the 2, tho I don't consider that a "flatout lie" either, since. well they were romanticaly involved, even if he didn't love her.
and we have a fundamental divergence in what you consider a "demand"
"tell me everything" is not a demand at all, its a request (which is the exact opposite of what a demand is)
Don't know why you are making the argument "she used his amnesia" I never said anything contrary to that, and I would like to add, NONE of Geralt's friends disclosed anything about Yennefer either
again the core issue: HUGE difference between having a cooperative Triss, and a Triss that requires "demands".