I live in apartment building its got some older people in it

anyway i heard my window being moved around or something and i notice like a spot you could see threw the blinds and seh was looking in at me

then i quickly got up an tried to cover the spot an kinda looked out an i saw her but she was pretending to be sitting down on a chair :\ what should i do about this i got spied on and feel terrible why didnt she mind her own business?