The letter is not an acceptance letter because the request had implied terms that Ms Ford will not agree to.
The true translation of the legal weasel words that her lawyer used is: I WOULD agree to meet with the Senate committee, accept that I do not accept the terms of the Senate committee and therefor will not show up for a hearing on those terms.
Grassley should read the legal response of Ms Ford correctly, as a rejection of his request to her.
FYI.
A source close to the process who supports Kavanaugh told CNN, “This is not an ‘acceptance’ of anything at all. The email doesn’t even say she will testify. It says she will ‘provide her firsthand knowledge’ but it doesn’t say how. It says she will do so ‘next week’ but doesn’t say when. And it says the rest of the terms are still up for negotiation. It ‘accepts’ nothing at all, but the language is very carefully calculated to give her credit for having accepted.”