We never stayed that far back, but we alway stay around the aft of the ship, room 212 something cat 9. I did not get a chance to see if you room was a cat 9.
For us the noise level is not too bad. We hear a little noise when they set up the dinning room above us (Parrot Cay ) while we are changing, but not more that what you hear in an office building when furniture is being moved around. The loudest noise is the engines when they are docking or manuvering. Unless you like to sleep in late, this maybe a problem. Only when we reach back home to PC, do the engines come on early.
The cat 9 windows are great, and it is quiet, but a lot depends on how sensitive are your parents to noise.