My baby is coming up 4 months old. She only sleeps in her cot and has just started sleeping through the night. My issue is how long it takes her to fall asleep! I’ve followed advice online and she takes all her naps in a darkened room with loud white noise. We have a short nap time routine and at bedtime we have a well-established routine of bottle, bath, massage, white noise and bed. I always try to put her down drowsy but awake by watching her sleepy cues which normally mean each nap is around 1.5 hours apart, there or thereabouts. Her naps are short (30-45 mins) and she often wakes up crying. It takes her at least half an hour to fall asleep and during that time she writhes in her cot, sometimes frustrated and sometimes just deliriously happy, despite being clearly tired beforehand. Am I doing something wrong?