Question: why did urmila slept for 14 years?
Answer: During the time of exile, Laxman requested Urmila Devi to stay back in Ayodhya. He wanted to serve His dear brother and sister-in-law, and hence wanted to stay awake and alert all throughout the period of exile. ... And so, Urmila Devi slept for 14 years while Sri Laxman did His job('Ram seva').