Thanks for your kind reply but I haven't visited her house yet so there is no question to put pills in tea bottle. I want to visit her house first time to complete sarah quest.When you visit Ms Taylor house the first time at Sarah’s quest, to take a picture for Ronald, you didn’t put sleeping pills in her tea bottle, so you can’t continue.
As Walkthrough say’s:
Ms Taylor:
Once you have given the picture to Ronald (Sarah quest) if you have placed the Sleeping
Pills in the Tea bottle when you took her picture (Sarah quest) you can return to Ms. Taylor's
home after midnight. If you have not completed these two steps Ms. Taylor will always be
awake.