Seems to me that you are making the assumption that b/f who earns $40-60K is helping raise the children. Why do you think such a thing?
Well, if she has had deadbeat boyfriends & Dads in the past...I was assuming she would be shrewd enough to at least get food & rent money out of this one lol. Even if is $30,000.00 only in her parents house, I assume for that area is do-able?