The godmother of my child has become a toxic force in our lives. Can I remove this person from being my child’s godmother?
No, sorry, but you can’t. Your child’s godmother will always be godmother because she is the one who witnessed your child’s baptism in that capacity.
If you are unable to make peace with this person – which would be the best solution and I recommend the books listed below for assistance – you can still distance your family from her. If your child doesn’t have a godfather who can take over full responsibility for godparenthood, you can ask a Catholic whose orthodoxy and spiritual maturity you trust to act as a spiritual mentor to your child. Although godparents ordinarily act as confirmation sponsors, your child could ask such a mentor to be a confirmation sponsor at that time.
Of course, if your child’s godmother eventually matures, changes her ways, and is interested in fulfilling the responsibilities of godmotherhood, you should seriously consider welcoming her back into your child’s life.