I would do a bit larger than normal water change. Make the new water a bit warmer than what's already in the tank. Add a teaspoon of standard aquarium salt to every five gallons of your new, treated tap water. Salt will calm the fish. The combination of the warmth, pure water, and salt will ease the stress on the fish and if she's ready, she'll drop the fry.
"Fear not, my young apprentice. Just change the tank water."