My XH married a woman as you describe. In the beginning, she was good to them. I was relieved he married a "good" person because he sucks so much as a dad. Her kids are mostly grown so I figured she would have the motherly instinct to keep my kids safe, comfortable, and make them feel like a part of their new family.
Boy was I wrong! Once married, she has changed. They have purchased a "vacation" home in another state and still maintain a small home here for EOW. His work has offices in both states. Their Dad is now in that state most of the time and is NEVER available to see them, except EOW. She no longer spends time with the kids when they are at their house. Even if she is in our state, she has better things to do.
While she is not mean to them, she makes our kids feel like strangers visiting at their Dad's house. She has become his #1 priority. The kids feel it, see it, and are hurt by whatever is going on over there.
This is a difficult situation to be in, but what I am hearing/reading, she is pushing you. She is manipulating you. She is telling you everything that is wrong, but those are the things that feel right to you. It's working because you are second guessing yourself.
Keep true to yourself.
"The only thing left to do is forgive and forget. I want to forgive you and I want to forget you!" ~Lauren Conrad
~Feel your emotions, but control your behavior~ Unknown