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What you have done is adequate to protect yourself. The State will not allow a guardianship over a competent adult person (that would mean that she could make your decisions for you, even against your will).
However, if you want to be more thorough, you can form a trust and name her trustee. This is a common way to make sure that she is in charge. Your trust would be for your benefit while living and you would be trustee as long as you are of sound mind. Should you become incapacitated, she would become trustee. In addition, she can a general durable power of attorney.
This (a trust) is the most common way to ensure what you are proposing.