Mother's Little Helper quest glitch

I can't seem to properly complete the Mother's Little Helper side quest. I'm in Mrs. Cheney's house and I'm able to do the first eavesdrop prompt, but when it marks that complete and moves to "eavesdrop some more" the lady only walks halfway up the stairs, stops on the landing and just stands there FOREVER. I've tried waiting under the desk, I've tried leaving the desk as soon as given the option to and creeping behind her as she starts going up the stairs...but no matter what, she never goes all the way up to the top floor to give me the second eavesdrop opportunity. My only recourse appears to be getting myself spotted or taking her down before the second eavesdrop, both of which cause the "eavesdrop some more" item to fail. I know you can technically complete the quest without that, but it bothers me to not have all the checkmarks.

This game is sooo buggy, but usually I can reload a save and eventually get past the bugs, but I've tried reloading for this one a dozen times and every. single. time. this damn lady just parks herself on the landing and never goes upstairs.