I actually understand what your fiancee is saying. For me, at least for awhile, attending a Catholic Church could actually be a distressing experience, partly because I was confused about some problems I was having, but I didn’t have the same issue in Non-Denominational Services.
As far active worship goes, that’s got to do with how much you mean it. People who refer to uniform and recited prayer as inactive, really are just reciting. When you say the Our Father, or one of the other prayers at Mass or elsewhere and think about each word, and mean what you’re saying to God, then the worship is just as active, if you were praying “freely”.
I would encourage you to talk with her about this more in depth. What specifically bothers her? What do you mean by she is really against the Catholic Church? (Is it mostly based on worship style, or does it have more to do with other issues.)
You’ll also want to talk about her attitudes toward marriage itself, how does she see the sacrament and her attitudes towards divorce. Are these also very feelings based? Or does she understand marriage as a covenant, and love as a verb, rather than a noun?
I would encourage you to think about if you could attend a service she’s more inclined to, as well as her coming to Mass. This however, could be a problem when there are children, but there are people with strong interfaith marriages. If attending Church together is a priority for you, and not something she feels okay with, then I agree you might have an unpleasant decision on your hands.
As far as other worship styles within the Catholic Church go. I’m not sure. I’ve been to Churches with more contemporary style music which might appeal to her, but I think that whether that’d be enough would have to come down to an examination of her reasons and feelings.