Hm...what do you think about asking her to write them down instead? You could tell her that you want to address her complaints but are having trouble remembering all of them, so you thought a solution would be for either her or you to keep a list so that you can cross them off once they're done.

And then there's the side effect of seeing them written down--perhaps she is unaware of the number.

And crossing them off would help her see your efforts.

And writing down complaints that you can do nothing about *should* appear silly to her after a time. It would also encourage her to consider whether this is a write-it-down type of complaint, and having to think about that could curb her tendency to give voice to every irritant.

You'd have to be wary of using the list to mock her--you are to take her complaints seriously.

Marriage is the triumph of imagination over intelligence. Second marriage is the triumph of hope over experience.
(Oscar Wilde)