Make a refference about her head being jammed up the other end and point out that's she is prolly right. You n her don't hear alike. Jkjkjk Sit down with her, talk things out, and tell her that every now n again ya might need things spelled out in crayons. Gets me thru a few squabbles with the missus.
Sometimes people just assume others are mind-readers. Your girlfriend sounds like one of those people that doesn't want to bother going through the trouble of expressing her needs and emotions properly and still wants you to get the hint. Explain to her that if she wants or feels something she needs to be as subtle as a gun and spell it out for you clearly so that you can understand her better.