How does you daughter feel about this situation? Does she think your fiance is pushing in some way or is this your interpretation of how your daughter feels? I think it would be good for your daughter and fiance to have a sit down talk about this and come to an agreement on their own that hopefully suits them both. In stead of you being in the middle let them talk about it so you don't end up just being a messenger who could get the message a little mixed up when you try to deliver it back and forth.

That's just the way I would try to handle it if it were me.