Do Guinea Pigs stop eating when they are in Labour?

I have a heavily pregnant Guinea Pig that I have no idea when shes due, but because its her 1st litter (she is only 5 months old) I want to be around incase something goes wrong. Her pelvis was almost a finger width apart since 1 and a half weeks ago and for the last 3 days I've been able to fit my thumb between them. She is rather large and you can feel and see the babies move, I've been able to feel kicking for a good month now. She sits around all day but is always hungry and always wants food. My question is, someone told me they go off there food b4 they give birth? How long before they give birth do they stop eating? and if she is eating tonight will I be safe to sleep through without checking on her?