I don't understand how you've been there 10 years, get propped up and promoted and are still fairly useless. Maybe they fired her because of you? If you're incapable of doing something that is your job without explicit guidance, then your termination is most likely appropriate. No one has time for hand-holding in the real world, and the ones who take the time to do so should be regarded as saints. You, however, decided to spit in her face and shit on her name when the opportunity presented itself.