A watercolor? The only paintings I've seen of the AP, or at least that I have saved, are these two:

If the image name is correct, the first one was painted in 1841, plus it is not from the correct side of the palace, so we can't see if the balconies existed then. I have no idea if the other two balconies were original to the palace or added somewhere down the road. We do know, of course, that Alexandra's balcony was added while the family lived there.
The second painting is of the correct wing, but with all of the shrubbery in the area in question, I can't tell what's over there. Under the awning on the side of the palace, there's a door with what looks like just plain steps leading down from it. According to the plan, you can see steps on there, but I assume they lead down from the balcony. They also don't lead out
away from the palace itself. Of course, the same question applies for this painting. I don't know when this one was done, nor do I know when the balconies were part of the palace, so perhaps this was before the balconies were constructed, and it used to be that there was just a door with stairs. The shrubs also seem to be right up against the rest of the palace too, so it seems doubtful that there's supposed to be a balcony hidden behind there. My depth perception may be off, considering it's just a painting, but I don't think there's a balcony there.
It just occurred to me that for all I know this painting might be flipped and maybe is actually of the right wing. :/
My, information on these balconies is elusive!