As much as you can worry or care, sometimes it just isn't enough to 'help' others. It's questionable, too. Just your own perspective, and maybe - just maybe, you're forcing your own ideals upon her life. Maybe she doesn't even care about love, she's just desperate for some company. And maybe, avoiding loneliness is the best choice, if you look at your possibilities. For now, she has someone she can marry and who can give her some stability in her life. Why would she refuse that? For what purpose? Because maybe, in the future, she may meet someone she truly loves? Is it even possible to keep going on on your own, without anyone out there to support you?
I do agree with you, but... some people just grow tired of waiting, of hoping. They just settle down with what they have. When you're not a teenager anymore, you have to look reality in the eyes, and deal with it.
I'm scared of that too. Scared of be fine just living a lie, rather than pursuing what's important. But then, what if you never manage to find what's important? What if you don't even know what is important and what isn't?
So many questions, and yet no clear answer. Only time will tell! In the meanwhile, the only thing one can do is to stay true to his or her own ideals. If you believe in something, stick with that until you can. When you can't, try to survive. Try to breathe. Nothing says you won't be able to be happy if you settle down anyway. Maybe she'll fall in love with her husband, maybe it'll be mutual and what not. In the meantime, I'd better just go to sleep.