Room with glass windows as a walls.

My daughter moved from first floor townhouse apartment to 42nd floor skyscraper apartment and fifty percent of her apartment walls are actually glass windows from floor to ceiling now.

I helped her with setting up her system at old place and the sound was pretty decent however new apartment acoustic wise is total disaster.
 Of course I did put her system together at new place but sound is terrible. She actually understands all my explanations about acoustic issues at new place, but she doesn’t take it seriously. My daughter  actually listens to a lot of music, sometimes for hours however I wouldn’t call her audiophile, probably just a serious music lover and I understand that she will have listening fatigue pretty soon at her new place.  

Acoustic treatment probably would be limited or refused due to esthetic and design incompatibility. Has anyone experienced setting up a system in such conditions, any advice?