Karina - Emma is right the boobying back to sleep would be a sleep association Claire has - do you booby her to sleep in the day - maybe try putting her to sleep during the day drowsy but awake and then do this for her last feed at night and then when she wakes during the night she hopefully won't need the boob to get herself back to sleep - does she have a comfort toy - little blankie or teddy that could maybe take the place of the boob when she wakes.....yeah I don't mind a bit of grizzling but my DD does full blown hysterics and I really can't cope with that. I am going to have a look through some of my no cry books and see if they have any other tips for you.
Laurin