Aww, she sounds sweet! Well, when my younger one was that age (he is 13 months) my pediatrician told me "sleeping through the night" at that age is defined as 6 hours. Sounds like she is doing more than that, which is great for you!
I did a painful version of cry it out for a night or two with my older son. It killed me to listen to him cry for 45 minutes. He slept with us for 2 years. Mommy was just a big softy. In retrospect, a little too long.
With son #2, I decided the most I could listen to him cry before I swooped in was 10 minutes. When he was about 6 or 7 months old, I tried to get him to sleep in his crib (was co-sleeping). I would put him in and tell him I loved him and go. Then I stared at the clock. He cried for 9 minutes once. Most of the time it was 3 or 4 minutes. He sleeps better than his brother ever did. My husband and I sleep better. He is so much more cheerful than his brother was, and I think it is because his sleep habits are much better.
Anyway, my point is try moving it 10 minutes earlier a week, for all the reasons you stated. Slow and steady wins the race :)