I guess I'm on the other side of this picture. I have several old friends; and one, in particular, who I would consider my "fourth sister." BUT, when she lived out of town we went months at a time without calling. You just get wrapped up in day to day life, the kids, activities, work, etc. Right now, I see her almost daily, but it's due to work not because we actively seek each other out... I enjoy chatting with her often and wonder why I didn't try to call when she was living further away. I have a flesh and blood sister who lives four states away and I only call her maybe 6-8 times a year. She calls me about the same. BUT, when we do call, we are usually on the phone for hours and have a hard time hanging up because we have so much to talk about...
I have to add that I'm a somewhat insecure person, so if I'm calling someone "just to chat" I sit there and wonder if they are busy, if I'm calling at a bad time, if they even want to talk to me, if I'm annoying them or boring them (it's just how I am)... If they call me, I love to talk and hear about what's happening in their life, but I'm always second-guessing about making the call myself. I guess what I'm trying to say is that we're all different and it's hard to judge what is going on with your friend without knowing her. Probably the best thing you could do is TELL your friend how you feel, more than likely she has no idea that this is hurting your feelings. I would have felt just awful if my Dfriend had told me my lack of calls was hurting her feelings. Now, I'm going to have to ask her!!!