is the grey brick only by that room then?
The master bedroom originally had 2 windows. For whatever reason they sealed off the window that faced the back of the house. This is the side Jeapes was on, there was no window to the master bedroom. The newer part of the house had red brick the older part gray brick. The window she described on the gray part is the boxroom. The windows on the red part (moving from right to left) were where the twins were and then a bathroom window and then 2 windows above the coal shed.
The master bedroom window is actually on the side of the house with the front door. What Jeapes called the front door is actually the kitchen door (often called the back door but if you want to get technical it is a side door because that is actually a side of the house not the back. The back is actually where the coal shed is).