If by "room divider" you mean a separate bedroom, then the answer is yes. The master is separated by a regular door. As for noise, My guess would be LK, simply because of the pool being in the Nemo are, but again, that is only a guess.
As far as noise goes, remember, the buildings are brand new construction! The rooms are 1000% more soundproof than most Disney resorts we've stayed at. Of course you'll hear some noise perhaps from the hallways but we hardly heard anything during our stay and I'm really sensitive to outside/surrounding noise in hotels.
I would pick the theme you want over how much noise you'd experience~
If by "room divider" you mean a separate bedroom, then the answer is yes. The master is separated by a regular door. As for noise, My guess would be LK, simply because of the pool being in the Nemo are, but again, that is only a guess.
Here is the AoA FAQ thread. You might find someone who has stayed there in that thread that can give you a concrete answer. There are a couple of pics in the first post that appear to me to have a pull down shade attached, but it's hard to really tell if that is what it is. Good luck!
Looking at those photos again, it appears that those are the doorways between the table and the master. You might be able to get some of those 3M hooks that stick to the wall and are easily removed without damaging anything. Then you could hang a shower curtain up across the opening.
I guess I'm not seeing anything like a pulldown shade in the photos, but there wasn't anything like that in the family suite. I don't know how many people you are travelling with but it is possible to let your 3yo to fall asleep in the master bedroom bed and move him or her when everyone is ready to go to bed? That way it's more separated/quiet/darker, whatever you need it to be for that time.
One nice thing I thought was great in the family suites was that the lighting was great. You could have the lighting be as bright as you need it but at night, or even in the afternoon with the drapes closed, you could still have lights on and have it be more subdued and soft. The design team did a great job at making the family suites as family friendly as possible in so many ways and yet still practical for a hotel.
Looking at those photos again, it appears that those are the doorways between the table and the master. You might be able to get some of those 3M hooks that stick to the wall and are easily removed without damaging anything. Then you could hang a shower curtain up across the opening.