I agree with everyone that has suggested you do some research elsewhere. What you have asked is not an easy question to answer because none of us know exactly what level of dominating she wants.
Please please please discuss a safety word with her. When you start experimenting with BDSM you start messing around with a variety of different comfort levels. You might think you know when enough is enough now, but keep playing around in these areas and I guarantee you will there will be a time when she really does mean no and you keep hearing yes.
Actually, this is where BDSM gets awkward because to make it work you have to be able to talk openly about want you want and these wants can get weird.
'People are never perfect but love can be. People waste time looking for the perfect lover rather than creating the perfect love' - Princess Leigh-Cheri from Still Life With Woodpecker.