Insomnia
For some reason, Nicole has had a rough time sleeping the last few nights. She usually sleeps all through the night with no trouble (except for maybe a little trouble falling to sleep sometimes).
It started with her crying in her bed at 1:30 AM two nights ago. That night I went in and calmed her down, but it wasn’t 5 minutes before she was crying again. I spent the rest of the night trying to help her go back to sleep. She’d seem to nod off to sleep, only to wake up after only a few minutes crying and needing to be consoled again. Finally morning came and I gave up trying to help her fall asleep and gave her breakfast. 
The entire next day she seemed sleepy, but wasn’t able to nap. She had moments of being fun and perky, but she kept laying her head down on the couch or on my lap. When she did nod off, she’d wake up crying after only a few moments. She walked slowly, her lids seemed to droop, and it looked like she was developing dark circles under her eyes. When bedtime came she went to her bed and just stood there staring at her bed as if unable to muster the energy to climb in. I tucked her in to bed thinking she’d happily sleep the night away, but she didn’t. Soon she was crying again. Zach and I both went in to calm her at different times. I even said a little prayer next to her bed. Zach took her to our room with her water bottle and Curious George. I slept on the couch (I was exhausted from being up all night with her the night before). I was hopeful in the morning because I hadn’t heard her cry, but later that evening, Zach reported that she woke up repeatedly.
She spent the second day similar to the first. She was tired the entire day, but couldn’t really nap. She fell asleep briefly at Kid City (child care at the gym) and when I looked in the windows I saw her in someone’s arms, not playing with toys. The entire day she wanted nothing more than to be held and read to and she was cranky.
When dinnertime rolled around she was so exhausted and grumpy that she refused to eat dinner and laid on the floor crying. Zach picked her up and put her in her bed to calm down, but when he looked in again, she was sound asleep. It’s now 5 1/2 hours later and she’s still sound asleep.
Could she have been having nightmares? She doesn’t seem sick in any other way.
I was three when I had the first nightmare I can remember, and it was terrifying. She may indeed be having bad dreams–poor little thing.
It could be night terrors, but I don’t know if that would affect her daytime sleep (though being overtired from not sleeping the night before could).
I don’t think they’re night terrors. Isaac had a few of those. Night terrors are really scary, it’s like the kid doesn’t even know who you are. They thrash and scream and you can’t calm them or comfort them out of screaming.