"That, between Monday and Wednesday, not knowing the precise date, when they were leaving the residence through the main door, to place the children in the respective crèches, MADELEINE left running to the left, to the extreme opposite of the residential blocks where they were lodged, playing with the twins. That they walked down next to the most remote end of one of those blocks, not knowing exactly which one, and the three children got into one of the gardens at the back. Then they walked down the inside alley at the back, next to the hedges, up to the street that led to the secondary reception." (GM)
Is it possible to go directly from the west end of the carpark of block 4, around the west end of block G4, into the garden of apartment 4F ???
If so that would fit the way the childrens' route is described above.
West along north side of block 5 and along north side of block 4, then around the west end of block 4, into garden of apartment 4F, and then out 4F garden gate into the cul-de-sac section of alleyway, then east along alleyway.