We've tackled this topic several times, but I do agree an English version should have been produced at the time.
Some still insist that an English written translation of the PT reported speech version somehow got magically instantaneously translated for the witnesses to read prior to signing. How on earth that was supposed to happen in real time is beyond my limited imagination.
I'm not even certain that the interpreters read out the PT version in all instances, although I can accept that they may have done.
But you're still signing on the dotted line and have to just hope the interpreter is accurate. To be fair to the lady, she may have just been someone that someone knew who had a working knowledge of English through her job.
It's equally possible that, in the eary rush, that they weren't. I don't have Kate's book to hand to see if the early ones were read back or not and I can't find anything conclusive in the files beyond the standard "reads, ratifies and signs" blurb.
As an aside, in one of Russell's rog sessions (when the recording didn't work, I think), someone typed up a statement, presumably from notes, and he went over the wording with a fine-toothed comb... and that was all in English.