there is no evidence that glass performs differently than drywall...except in the lower frequencies.
the challenge with glass is that you can't really hang art or other things like you can with drywall...so you get bad flutter echo.
Modern rooms also typically don't have carpet. I'm guessing this is true for your daughters new space....so rugs with carpet pads will help.
Furnishings can also help. Again modern furniture won't be as helpful as it's typically reflective compared to soft and plushy. Clutter can also be helpful. You don't want a sparce room.
best of luck