Early morning scares and weird obsessions

This morning around 5 am A. came into my room again and said "my blanket's all fold up." What I heard was, "mama I threw up," so I was immediately wide awake and asking her to repeat her problem. Thank goodness it was just a blanket issue. Both girls, but especially A., have this weird, new obsession with their blankets. The blankets have to totally flat and unclumped in their beds and if the blankets get at all messed up while the girls are playing instead of sleeping then there are immediate hysterics --because my girls aren't really calm about anything. In fact I will be walking to their room to tuck them in (and they know I'm following them), but it's still not fast enough and they start wailing about their blankets being 'all fold up.' On any given night there will be crying in the bedroom sometimes for a drink or because we forget one of the steps in the bedtime process (skipping steps or doing things out of order is also unacceptable), but more often then not it's a bunched up blanket. B. will usually carefully lay her own blanket down and stays relatively calm as long as the blanket cooperates (heaven help us all on the days she's over tired and/or the blanket is a bit twisted), but A. has decided that only a parent can fix her blanket and just goes immediately to the crying as soon as she enters her bed. I have no idea whether to humor them with this weird fixation or to let them scream it out so they won't come bother me in the early hours. But I'm usually so relieved that she said 'fold up' instead of 'threw up' that I just take her back to bed and smooth things out. I guess maybe this will be a good thing when I decide to have them start making their beds!