I want to fix another switch to the light in the bedroom for my mom so that she can switch off the light from her bed. I need a circuit which will work as follows:

switch on the wall => switch next to her => light

ON => ON => OFF
ON => OFF => ON
OFF => ON => ON
OFF => OFF => OFF

In other words, the light should switch on only if one of them is switched on and not both.
Any ideas?