Chill out man. It's not up to you how other people work, you can only keep your side of the street clean.
How you are as a person, how you interact with others - these are the absolute most important things and they will be the things that get you work and repeat bookings. The singer has already said it makes her uncomfortable - a big warning bell should have rung right then.
I've been in part time bands with people who try to control everyone else and it never works. Unless they set up and run the band by their rules and this is clear from the get go, in which case I suck it up or leave depending on their ability to get me work.
Even then no one tells me how to work, how to learn songs, whether I can have chord charts or not. It simply isn't their business.