I have a woman who loves me, but is too old to have kids (46, I'm 32). I love her, but want a family.Cont....?

I know this is crazy, but she is willing to stay with me even if I have a family with someone else. Is she being desperate and unrealistic? We would be moving to the country (plans are already in place) and I can build two houses, one for her and one for me and my wife. Is this a crazy idea, or a solution to love that spans our different ages and cirstances? Plus, what woman would agree to be with me if I love another, too? I am ready to break things off completely, but I feel that a love like hers shouldn't be wasted. Our ages and me wanting to have kids is breaking us apart. Any advice is appreciated.... (I know this question may upset some people, but please be nice. I still have a lot of feelings for her).