I'm not so sure about the bi thing being a reason. A poster above mentioned how real life affects online routines (and the opposite). I agree with this line of thinking. You simply cannot control the demands of her life and her availability. In fact, I think this is rather healthy that she is possibly not allowing online social media to affect her real life. Think about your own internet activities and your expectations of her availability; are they reasonable? If you are sitting around waiting for contact from her consider what you are missing in real life. It sounds to me like this has become habit forming and that really isn't very healthy.