The stupid question was "Did you help him escape because you are a silly sentimental woman who still loves him?" or words to that effect.
(The 100 today had a teenage girl doing just exactly that. It was a horrible decision made by a pathetic child who is a discredit to her gender.)
"Why did you wait before you told us?" was three questions earlier.
I just checked. You're right, she does say it's stupid after they ask whether she wanted to help him escape, but in my mind it's a natural question connected to why didn't she tell anyone
FBI:
Why didn't you inform the bureau about Tom Keen after uncovering his initial deception?
Lizzy:
I wanted to investigate him
FBI:
why?
Lizzy:
so I could see how deep this rabbit whole would run
FBI:
you didn't want to help him escape?
Lizzy:
That's really a stupid question