sleep for 6 hours during night time

Ee Shuen slept from 10.30pm till 4am last night, almost about 5 1/2 hours! This is the 1st time ever she sleep so long! Mummy was so scared even she have a long sleep. Because she cried for quite a long time before she went to sleep. I think she's too tired of crying, she used up all her energy to cry out.... That's why she didn't wake up after 3 hours for her milk.