How to stand up to your boss?

Kim • engrkikay ❤️

I have been asked to proxy for a seminar last jan20 because my boss has a wedding to attend to. Another seminar is scheduled again this feb 24 and she said that i have to attend it but i have other plans which is i will be a godmother to the christening of my cousin's baby. She said no and keep telling me reasons why i should be the one to attend. I know that the seminar will be for my career but i feel that she is being unfair in terms of giving me work assignment. Is she being unfair or i'm just being illogical?