Posted: 13/10/2013 at 21:50
If any of the branches overhang your mother's property she is within her rights to cut them back to the boundary line (assuming there is no TPO), but no further. She must also return the cut branches to her neighbour.
If they are simply large trees then there is nothing your mother can do unless the trees are causing physical damage to her property or drains.
Not quite the same as your problem, but a few years ago the people living behind us stuck a snotty note through the door demanding that we cut back a tree which was putting their garden in shadow. I took great delight in telling them that the tree was actually growing in their garden. The previous occupants of their property had built a wall about 3' into their garden for some reason and the tree had grown up behind it! Had they bothered to speak to me when I was in the garden it would have been easily sorted. As it is they haven't spoken to me since. Ho hum.