Is the yolk now absorbing? Is it getting smaller? Once it's pretty much all absorbed she should be fine with the others but just watch for them pecking at her rear end. Chicks are fine to go without food or water after hatch for 72 hours but I like to get them eating and drinking between 24 and 48 hours. I move chicks into the brooder 24 hours after hatch and let them settle for a few hours. They generally just go to sleep as they are still recovering from hatching. After a few hours I start tapping my finger in the chick crumb so it makes a noise like a mother hen would make pecking in the food. This should encourage them to come and investigate the food and start pecking. Whilst there I also gently start dipping their beaks in the water so they know where it is. Once you get a few eating and drinking the others should follow suit.