I cant find a section for sleep ...

Anyways my bub 4 1/2 months seems to cry in her sleep, sometimes just a wimper, sometimes a full on cry that wakes her up. She really tosses around in her sleep too, this to wakes her up. I dont know wether she is in pain ( shes quite unsettled most of the time ) or if shes dreaming? do babies dream? i hope i dont sound silly