Although people have said she doesn't really love him I don't agree with that.
That is a possibility, it could also just be a blip that they are going through, relationships go through many ups and downs, this can be one of them.
They both need to sit down and have a proper talk about their situation as we obviously don't know all the angles. If they both come to the conclusion that it is a case that they don't love each other anymore then they need to end it.
It could just be a case that they are struggling to make time for each other so they won't have anything to talk about, if that is the case then they both need to make a massive effort to make time for each other and get back on track