My XW and I did not go to mediation as both of us were agreeable on everything. My friend, that is a judge, told me there is no sense in mediating over what you already agree on.
You can't control how she perceives you just don't let the love you have for her cloud your judgement and cause you to accept something less than you want because she portrays you as a bad father. Don't let those words scare you into accepting something you don't want.
I would have drained every account I have if my XW tried to take full custody of my kids from me and was not agreeable to 50/50.
You don't have to be mean or declare war you just have to not budge off what you want. You can say "No, I don't agree to this" in a very respectful and polite tone.