Just watered my peace lily because it was drooping. Will it stand up again and, if so, how long?
Yes, a wilted Peace Lily should recover after it receives some water. Give it over night, and if the plant is still droopy, set the plant in a tray of water to drink for an hour. Then allow any excess to drain away to avoid roots sitting in soggy soil.
Here is an article to refresh you on the care requirements.