You have set up an expectation in the friendship and have broken it. Why wouldn't she be upset? Do you think that you're the only one who's attached? Are you the only one who's happy to hear from the other?

I think if it's a problem for you that she gets angry, that you should talk to her about it. Tell her, I write when something happens I think you'd be interested in. I'm not going to bore you with the details of a boring day. Or whatever is going on - you don't want to talk to her when you're mad because you might say something you don't mean. Whatever it is. Be honest.

If she has a reason for your change, if she can prepare for it, then she won't be thinking to herself, "oh what have I done now?" Probably she's mad because when you didn't text, it made her feel bad, and she's mad at you for her feeling bad. In truth, it has nothing to do with you, but to her, I think, it doesn't feel that way.