Whatever took the eggs will also take the new born chicks as soon as they are born. So either they take them now or they take them later if you just leave them loose under the house with no protection from intruders.
If you want her to be under the house you could enclose it under there so nothing can get in or out. That way it could be a safe coop space for her. I don't think it will be practical though because it would be hard for you to get under the house to keep it clean and change her food and water on a daily basis. Is there no place where you could put her in a nest box to be safe? You can always bring her in the forage you wish her to have. But please try to protect her now because if you don't, any chicks that are born will probably be grabbed immediately and the mother may also not make it in their current living situation.
Good luck. It really hurts me and tears me apart to hear that some birds and their babies are left to fend for themselves completely like this.