Can a neighbour open a window on2 our back garden?

Thanks guys well, this conservatory was built b4 the previous owners of our place. What little i know of our neighbour she likes her own way. She has done several things wrong with this conservatory but, as we have bought our place knowing the conservatory was there, even if we didn't know about the problems, we have 2 put up with most of them. This window does encroach on our air space and I doubt very much if when the conservatory was originally put up that she would have sort permission of any kind from any1 as it has obviously bn constructed without compiling 2all the council say that can and cannot be done when erecting a conservatory. I have sort advice from just about every1 that provides fr3 advice and have rang the council 2 but, all have drawn a blank regarding this intrusion of our air space. I hope u guys can help me. Thanks again.