Q: Can i share apple music but not my credit card?

I just bought the apple music service, and chose the family edition to be able to have my girl friend use the service as well. I added her to the family, and discovered that she would be using my credit card now - hmmm.. I found this to be less than ideal, and figured there must be a way around this? Any of you have any experience with family sharing? This is my first time using it, and I'm having difficulties figuring out what it's used for.

Thanks in advance.