Well, I used the same routine because I was starting college. You don't have to let her cry it out for 45minutes, that is a little excessive, and I am not judging, but what I did with my son was go in eveyr 15minutes to re-assure that he is okay. He was 10months when I worked on it, and the first time it took an hour, going and checking in on him every 15minutes, and making sure that he had a bottle of breastmilk. And then, slowly over a period of two weeks, he got used to it. By the 4th time, he only cried for 5minutes. Now that he is two years old, he still gets upset because we have to understand as motheres, our children love us. We're their care takers, and when we go away, they feel a sense of fear. Your doing the right thing, all though alot of other parents may criticize us, I do not have a second parent to help me, it's just me, so unfortunately I had to do that to help him learn how to put himself to sleep, and it worked because if I had a second parent, then that second parent could help me with the night time feedings, and the homework that I have do. I can't have my child up all night, etc. By the time my son was 12months old, he was sleeping through the night because I made a decision to do it that way. For the first year, we had a routine, but no bedtime routine. I instilled the routine, and children love routine because they know what to expect. There are good and bad with routine, I've found. It's good that the child knows what's up, but the hard part is when you go off that routine, my child freaks out. If dinner is past the time, etc. But by showing him patience and calmness, he got used to the fact that he can't expect me to get something for him right away, and I make him wait up to 5minutes. Sometimes he goes off and plays, and forgets about it, LOL!
Anyways, hang in there, your doing fine. Each child develops differently, but for my son it took about two weeks, although the first 4 days he transitioned into the routine nicely. Two months later, up-all-night was history.