Carefully allowing your child to learn to soothe herself to sleep will not hurt her. In fact, the ability to soothe herself will be a tremendous gift throughout her life! If you carefully watch your child for cues, and make good choices about when to soothe (when sick, teething, screeching vs. fussing, etc.), then your child will not feel abandoned or extremely stressed.
I think it is highly stressful for a baby to NOT know how to go to (or back to) sleep on their own! Imagine if you needed help to go to sleep, every time you woke up in the middle of the night? If you HAD to have your back rubbed, or be given a drink, until you fell back asleep. How incredibly upsetting!
If you adore your child, and give her a ton of attention, carry her a lot, interact with her, kiss and cuddle her all the time, etc.....then your child will be a happy, grounded, loving, affectionate little girl (and then woman). Allowing her to fuss herself to sleep won't change this, and it is a temporary measure. After a short while, she'll figure it out. My son is almost 13 months, and we have used careful, sensitive cry-it-out methods (check out Weissbluth) since he was about 5 months old. He is completely attached to me, with no abandonment issues. He sleeps in his crib, and LOVES it there! (And he used to sleep in bed with me, so we made the switch successfully!) He gets 12 hours of sleep per night, and 2 naps a day of 2 hours each. And he's done this for ages!
Lots of sleep = happy and healthy baby. Honestly, read Weissbluth's "Healthy Sleep Habits, Happy Baby." It's based on good, sound research. It's all about restful sleep, and he knows his stuff!
Good luck! You've given your daughter such wonderful comfort (and nutrition!) these past 11 months. It's ok to let her take the next step and fall asleep on her own. She's older, and smarter, so she'll kick up a storm for a while. But give it a couple of weeks, and you'll be so surprised with how well she does!