The questions that pop into my mind are is your baby held a lot. I seem to remember children who are not held enough, rock themselves to soothe themselves, but it is out of deprevation, it isn’t a good thing, it is a sign of something essential missing.
I would also be curious about what @bkcunningham and @SpatzieLover mentioned.
It also could be a disruption in brain waves during sleep. From what I understand there is not really a such thing as half awake, one is either awake or not. But, I guess you mean she is very groggy, or maybe asleep, but blinks open her eyes at times? I just did a sleep study and it was very interesting what little I talked about with the woman who set me up for the study. The brain wave patterns of people who kick during the night, or who have night terrors. Sometimes they have apnea, and the stop of respiration causes the outward symptoms. She didn’t explain why they think it is so, but all I can figure is the loss of oxygen causes nightmares maybe? Maybe her behavior is similar to sleep walking? I’m really not sure. Anyway, the results of my test was I have Alpha intrusion during my sleep. Alpha waves are supposed to be seen when someone closes their eyes but are awake. It is seen in narcoleptics and people with reumatological problems like fibromyalgia and rheumatoid arthritis, the conditions have chronic pain in common, but they really don’t know the connection between the brain waves and the ailments. Maybe there is some sort of sleep disturbance with your baby that she very well might grow out of? Since people cycle through stages of sleep about every hour and a half. Probably with eavh sleep cycle there is the risk she will go through whatever it is that prompts the problem. That is, if I am on to something, I might be completely wrong.