New system, large room, low listening level

My first post, and not for me; for my adult daughter. She wants/needs a 2 channel music system. She lives in the UK in a restored Georgian townhouse which was converted and restored into flats 15 years ago.  Very posh. She is on what we would call the 2nd floor, which in the day was probably the main floor of the entire townhouse.  15' ceilings!  Her main living space is 20' x 30', functionally divided into sitting area, kitchen, small dining space and small office.  It is totally an open floor plan.  Curtains on 3 tall windows on the long wall.

The listening position would be about 12' from the speakers which would located along, and close to, the short wall.  Aesthetically, she would prefer floor standing.  For electronics, no more than 2 boxes, maybe zero or one.

Listens entirely to music from the internet: Qobuz, Spotify, radio (Classic FM), etc.

She listens at relatively low levels, perhaps 75 db max.  Musical taste are classical, light jazz.

Would prefer British brands, or at least brands readily available in the UK.

Suggestions, please.

Thanks in advance, Larry

devialet phantom reactors, if france is close enough :)
The Kef reference speakers are wonderfully dynamic at lower volume! For a larger room the reference 5.
The monitor audio platinum and Gold series are excellent sounding speakers very natural and warm and there a British brand.
on the cheap, get a couple of HomePods for stereo and stream from your phone. I use HomePods around the house as Roon endpoints. A little more, the ps audio sprout 100 is a preamp/dac/amp in a small package with 100 watts. I use this with either a pair of Jamo floor standing speakers or Usher stand mounted speakers. Read the review in TAS on it. I use it in my large office. 
At low level and that big room i can think of only one speaker that can give the extreme detail classical music can have. Quad 2812.

You will not get a lot of bass but enough for my taste. I do not own Quad by the way.