Not that I know much about it, but if your DF wants to argue about her "manipulating" you and developing bad habits by co-sleeping, you could always show him some information on what is good about co-sleeping. I know there's some good stuff on BB about it, and my DH is more comfortable with our co-sleeping plans now that he knows that it's a good thing for the baby as well.

And I agree with the other ladies - perhaps if your DF wanted to get up and settle her himself then he might see the practical benefits in co-sleeping.