C.G.
One of the things I did with my husbands ex was a co-parenting contract. It sounds complicated, but it is really simple. I let her know that her rules and opinions mattered to me, and she started listening to me. We sat down and wrote out bed times, meals, major rules and what not. Once she learned that I was not neglecting our son, or being a bad parent things got a lot better. It was easier on our son as well because he knew the rules would be the same no matter where he was. It eliminated a lot of confusion on his part and fostered more trust between all of us adults. My husband and his ex could hardly stand to be in the same room, so once she and I got our roles worked out, it made it a lot easier on everyone. Playing devils advocate for a moment, look at this from her stand point. She lost her husband (not saying it was your fault, his fault or her fault) and she make be over-reacting with fear of losing her daughter as well. If you make it clear to her that YOU respect her role as your daughters mother, and that you intend to make sure that your daughter does as well, it may ease tensions. Or it may not. I don't know the woman, but in most cases if you give respect you are given respect. I wish you luck in this, dealing with step children (most especially if you love them dearly) can be difficult. Let us know how it goes...