my 12 week old daughter has just taken to the dummy, however i am unsure of how to use it with her and when to offer it to her. ie, during the day at play times, to get to sleep then remove it, during sleep etc?

today she quietened when it was offered to her asi was rocking her to sleep and then half an hour into sleep she awoke when it fell out of her mouth and then she was wide awake, (though still tired). is there anything i can do do avoid this happening?

anything else i need to know about how to avoid the pitfalls associated with using a dummy?