Honey, something is either missing from your story or your pastor is deranged. I'm sure it's the former.
If you have repeatedly asked the lady for music, and she has never given you music, and you need this music in order to play for the choir, then clearly you won't be able to play for the choir. If the pastor asked you why you're not playing for the choir, and you told him that she never gave you music, and he said "that's not how it is," then there's a piece of the story missing (or, he's off... but he probably isn't).
It's clear that your pastor expects you to play. If I were you, I would just sit at the keyboard (or whatever instrument) during rehearsals and services, and be in position to play. I speak often of proper posture and positioning. I won't go into it now, but know that it's important to be in place no matter what's going on around you. Obviously you can't play, but you can sit there knowing that you've done your part.
(One other thing, after you hear the song in rehearsal, even if it's too late for you to learn it that night or by the time they sing it, you can still learn the song and have it prepared for the next time they sing it (or the next, next time). The daughter is clearly an obstacle, but you can jump around her.
