The old addage "you cant please all the people all the time" comes into it big style.
As she came up 5 mins before the end, would have just told her there wasn't time . If we played all the can we have some x , can we have some Y and can we have some z then we might aswell just take a juke box with us.
We do this because we're good at it , if everyone could do it then the world would be flooded with Dj's. They can't so we do!
Wouldn't worry, wait til this weekends gig and it'll all be forgotten about and defo no refund!