I am blown away that the doctor is recommending to let a 6 week old fuss herself to sleep! I have never been fond of the cry it out method (probably because my kids just got more and more hysterical).
My boys both co-slept with me from the time they were born until they were about 2 years old. I could start putting them in their beds after they were asleep around 9 or 12 months, but if they woke up I immediately let them come back into my bed. By 2 or 2 1/2 they were more able to sleep in their own bed (or a few minutes of snuggle and then back to bed). My younger son was born when my older was 2 1/2 so there were some logistic issues there but nothing serious. And he shared a room with his older sister and sometimes would sleep in her bed which made it easier too. I nursed both boys, and it made the nighttime feedings easier, I just nursed them lying down. And there really wasn't any issues when weaning.
The boys are now 6 and 8, and they go to their own beds without a fuss. Occasionally one of the will come in to our room in the night, but I can usually just tell them to go back to their bed and they do (until their dad leaves for work at 5:30, then I just let them snuggle with me.)
So I'd say, go ahead and let her sleep in your bed as long as your okay with it. It's not going to "mess up" her sleep later on, and it'll make nights easier on the whole family. Do keep trying to put her in her crib, but go to her soon after she starts fussing, before she works herself up. (If she starts wiggling around before she's awake, you can try swaddling, and you can gently rub her check or forhead or arm and talk softly to her, to see if it will help.)
I'd just keep bringing her i