The period around 5am is a very common time for us (adults and LOs!) to wake if something is "not right" - it is a time when melatonin levels and body temperature are both at their lowest, and the final stage of REM sleep has finished. During this time period lots of things can cause wakings unless the whole scene is perfect. This is a common time for the EWs that are caused by overtiredness to happen. But, if the room is too hot or too cold, or any other kind of discomfort such as upset tummy, teething pain and so on, or even just that a bird chirped just outside her window and slightly startled her in the half-awake phase she is in...this is the time when it will very likely cause her to either wake or to moan about in a half asleep/half awake state.
Yes, it could be hunger, but I personally put that at the lowest suspected "culprit" on my list, unless she is waking very soon after that and eating a load when she wakes, and not eating well consistently through the rest of the day to fill her up with the food that she needs to make it through the night.
I would put temperature or teeth as the most likely suspects, unless you think there may be a routine issue. Temperature because it is the time of year where the temperature is fluctuating so much during the day, can drop quite cold suddenly in the middle of the night, or even end up having a random warm day and that warmth kicking in during the wee hours of the morning. Teeth, well, this is a prime age for some MAJOR teething to be going on and will prob continue for the next looong time!
