Speaker recommendation for married couple

again I will 

Again I will say Vienna Acoustics Mozart Grands. Why???? Because they are in the same family sound wise as SF. They cost a whole lot less used generally than SF. IMO you pay for the finish and looks for SF speakers big time. 

The Mozart Grands also have deep bass for a small floor standers. They are able to completely disappear. They are also 4ohm so a 70 watt amp that doubles is plenty enough power so you don't need to go crazy. They are in you price range used. The finish is better than most speakers in the price range. 

If looks are not an issue (not that they really look bad just not a show stopper) I would go also look at Golden Ear speakers. The ribbon tweeter are very musical and never sharp. Plus you get more bass than you would expect because of powered subs in the speakers. Also you can adjust the bass level allowing you to tone down bass in a smaller room. 

Take a look at standmount or floor standing from:
Ryan speakers, good value with Sonus Faber like qualities
Sonus Faber Venere or Olympica series very musical
Focal Sopra series great balance and resolution
B&W 800 series - either love or hate?
Audio Physic good at everything easy on the eye
Magnapan great at lower volume tough looks
KEF R LS, R series and Reference all great
You didn't mention budget?
Or what electronics you will use?

If your wife has "very good ears" why not let her choose. If she chooses something that is respectable in terms you agree with then why not?

Did she listen to the speakers in a dealer's showroom or at your house?  6' ceilings are extremely low, so you should probably get some panels mounted overhead first and foremost to try and 'disappear' the ceiling.  No doubt you are getting a lot of early reflections and comb filtering from the ceiling that are coloring what you and the Mrs. are hearing.