My 13 week old is a great sleeper at night - will sleep around 11 hours and goes to bed easily enough (I know we're lucky!), but during the day she will only nap in my arms. If I put her down at all - either awake or already asleep after being in my arms - she will cry and cry until she is picked up again. Any tips on how to break this habit?? If she doesn't get her naps during the day she is in a terrible mood.