I agree with your doctor, she is still really young. My daughter just turned 1 year old and she fell asleep the same way every night for at least 8/9 months...nursing and rocking to sleep. I think I started a bit late on getting her to fall asleep by herself, but she does it now and it's great! You should do what you want to do. If you don't want to stick her in her crib and let her cry, then don't! There is nothing wrong with that. I did it every now and then, but it is hard. Just try to start a routine.
Here's what we do:
1. bath around 8pm
2. read some books
3. turn off lights, put on music
4. she drinks milk (from a cup now, nursing before)
5. brush teeth/gums
6. rock for a few minutes till she's drowsy
7. put her in her crib, still AWAKE, but drowsy
Right now she might not have a real steady sleep schedule. (if she sleeps through the night now, you're blessed!) I would just start parts of this and then when she's ready-and you're ready-you can do the last two steps. If she's nursing at bedtime I know that is harder, it was for us. I'd just try to stop her when she seemed to be getting tired. I admit I was using a pacifier (until this week) so that helped. We stopped the pacifier this week and she only cries for it a few times, not at every nap and bedtime. It's been 4 days without the pacifier now! Yes, she is still young, but it's good that you are thinking about this now. If you do start it when she is 4-6 months old and not later (like I did) it should go smoothly. Good Luck!
p.s. A good article I read recently about this is in the August 2007 issue of Parents magazine. It's called something like "Get your child to sleep through the night." Maybe you can check that out.