There is also health issues to be considered too. At the moment we are doing vanilla do to her health and actually not even vanilla.

I would say that it depends whether sub/slave is showing proper respect to you. She gives you her gift of submission but without respect being shown then it is of little value. My advice is to let her know that failing is not exceptable and impacts you deeply. When she fails you fail, if she knows that and continues to fail I doubt that she is serious about the life outside of the sex and games. At that point I stop giving my gift of Dominance to her and let her be in total control of herself.