I agree, which is weird for me because I'm notoriously bad at staying in touch with people. I forget to call people all the time. But what stuck out to me the most is that she knows you get anxious when she's gone, and I think that she should make a huge effort to call. You are definitely aloud to be miffed, and I'm sorry you had to stress while they were gone.

Maybe make a rule with her to call you every night, to tell you their back in the hotel or something safely. Would that work?