I bet she will open up if you did. I was just thinking of a time that a close friend of mine (although because she's an ENTJ, I didn't realize that she considered us close) told me that she was upset with me because she felt I wasn't being there for her. I had been so caught up in my own issues (a couple of teenagers for one!) that I hadn't really noticed that I had to keep rescheduling with her because of things that came up. I didn't realize that she was upset about it. Not because I don't care, because I DO care...very much, but just because sometimes I can get SO caught up in the practical parts of life (like making sure bills are paid as a small example), that I don't think about other things. She opened up to me and was very direct about how she felt. At first, the conflict made me uncomfortable and attacked a little, but because I care about her....I listened to all of her feelings and let her get it out. I hadn't considered that she would feel that way. Once I realized how it affected her, I opened myself up and apologized. I told her it wasn't because I didn't care and that I would be more sensitive in the future. When I say something, I mean it...and I have really tried to be more sensitive towards her. I feel like our friendship has grown because of it, we've gotten closer and I've learned to have a little thicker skin because although there was conflict, we got through it...and I value her as a friend.
Different personalities make it hard to see things the same way. I think it's good that you opened up to her. Unfortunately, everyone can't always be there for us in the way that we would like, or love us the way that we would like and we have to accept them for what and who they are and love them anyway. I would LOVE to have deep talks about how I FEEL with my ENTJ friend, but she's just not equipped for that. So I have long talks about how I FEEL with my other feeling based friends. I've discovered there is a huge difference between the "N" and the "S" parts of personality, both in my boss and in my husband, who are both N's.
Unfortunately, as an ISFJ...I can tell you that I tend to place my family over my friends. (Well, over pretty much anything.) That's just how I am. I love my friends and I am a forever friend, but my closest relationships are those with my husband and children and sister (since I lack other extended family.) That doesn't make me any better or less of a friend than other personality types...it just makes me different.