DD is 16 months old and from the age of 6 months has slept 12 hours.. The past 2 nights she has been waking up multiple times through the night as early as an hour after she goes to bed.. It seems as though she just does not want to be in her cot. She stands up holding onto the side of the cot and cries and cries. Its heart breaking.. but I dont know what to to? Help?