My two cents:
I think it is hard to "force" a change in behavior with anything other than time. Teach her, guide her, and answer any questions she may have, but it could take time, maybe years. I've been trying to modify my wife's sexual behavior for a few years now (since before we were actually married) and it is working.
See, my wife is a very assertive and "type A" sort of gal, definitely an "alpha female." This description stops in the bedroom though as she was raised... with a strong religion context that ended up smushing her sexuality. Over the passed few years, I've just helped her break out of her shell and give her ideas of what things she could do when being assertive in the bedroom. As you may imagine, this is not a quick process, but over time it has started to work and she is enjoying herself much more while in a dominate role vs. just doing it since I enjoy it.
It is also important to note that I'm sort of passive-aggressive in life. I generally avoid confrontation (really don't like it) but want to control all aspects of my life around me. I am very much a "top from the bottom" as I only like to be tied down and "helpless" when I know the ballpark she is playing in. I often find myself wishing she could read my mind as I know what I want, rather than just doing what she wants.
I felt this could be helpful as a perspective from someone who is not really a "submissive" person while in chastity. I love being her "pet" or "naked slave boy" when there is a sexual part in it, but being told to wash the dishes in chastity sucks just as much as being told when free.
What has ended up working well for us is her acknowledgement that I am in chastity. Whether it is a sexual "reward" for doing something, or just verbal teasing randomly throughout the day. If we go a day or two without such acknowledgement, I start to find the ordeal pointless. During this time, sometimes she is in a dominate role, while other times a more equal role. Sometimes she even takes a submissive role as I tie her down, do whatever I want (while still being locked up) and usually end with an orgasm for her. We love our sex toys.
