If I were to tell her that I wanted to have sex, I think she would probably reject me and say something to the effect of "you never wanted to in the past -- too little, too late."
So what if she does say that, it doesn't mean that your stating that you wanted/want to have sex with her is invalid. She very likely will make a statement like that, to which you reply back "I know but now all I can think about is having a family with YOU."...or something to that effect. Of course if you don't honestly want children, don't make that statement. Speaking for my own perspective though if having children is important for her and you know that, you need to let her know it's important for you too...to have them with HER.
