Maybe he/she is hibernating, The room might be too cold. I think you have answered your question in the words of the answer... No sign of life :( Can you share a couple pictures?
Select as Best AnswerUndo Best Answer
Very possibly, have you checked the battery?
I admire your confidence in us but it really isn't possible to tell from your description.
Good one ;-)
How did you know it's a she?
As far as I know snails are both.
This is assuming you are talking about a Giant African Land Snail or similar:
Fill a shallow tray or dish with luke-warm water, about 1/2 inch deep, and place your snail in it. Use a cloth or paper towel to bathe the shell in the same water. The operculum will soften and fall away, and (if the snail is alive) it will gradually emerge. This may take up to half an hour if the snail is very sleepy, so you will need to refresh the water to maintain the temperature. It will be wise to have something tasty to hand when they emerge, just in case.
What is the room temp?
It could be just sleeping.