My fiance and I can not agree on how many children to have...?

I think personally 2 more kids would be fine. I know it sounds like a lot but you will be fine. Your right, this is nothing to end the relationship over. She sees how amazing you are with your little boys and she wants to have a couple of kids with you, that is really great. She sees you as a good father figure and wants to have more babies with you which will bond you two together forever. If neither of you are really sure if you will want more than 1 more then have the 1 child and see how you feel then. She may have 1 and decide that is all she wants and if she decides she would really like another one then you can figure it out then. Honestly there are plenty of couples that get together and 1 wants kids and the other doesn't and it is usually the one that didn't want any that changes their minds. Just don't let something like a number come between you and this woman you are in love with. All that matters is how she is with your boys, how much you love her and comprimising. 2 more kids isn't going to be the end of the world and like i said she may have 1 and decided that is enough for her.