@Shmenosan Looking at the areas in your BG image, your imported BG (and therefore the floorplan is about 10% undersized, but you are using full sized furniture. This means there may be a bit more space to play with than your plan would indicate.

Also, another idea for getting a third bedroom is to put BR2 and BR3 where the living room area is, each getting one of the windows. Then put the living room where BR2 used to be. This does reduce the living room to one window, and it may be a less pleasing view out of that window.