First of all, your confinement nanny is ridiculous. A naughty 3 week old does not exist! Ignore your confinement nanny.
As per pp, it sounds like a normal growth spurt. Are you feeding her until she naturally comes off the breast? If she falls asleep, do you try to wake her by tickling under her chin or her feet? This could help to give her a more substantial feed and send her into a deep sleep, so that hopefully moving her to the cot won't wake her.